bluuebunny/crossref_metadata_2025 huggingface dataset:
MICROBIAL FLORA AND LEVEL OF VIBRIO PARAHAEMOLYTICUS OF OYSTERS (CRASSOSTREA VIRGINICA), WATER AND SEDIMENT FROM GALVESTON BAYa
Authors: Vanderzant C. , Thompson C. A. , Ray S. M.
Published: December 2016

Aerobic plate counts at 25 C of freshly harvested oysters ranged from 2.3 × 104 to 3.0 × 107 and those of sediment samples from <102 to 3.0 × 106/g. Counts of water samples were nearly always <102/mi. Vibrio, Aeromonas, and Moraxella species predominated in the fresh oysters. Vibrio parahaemolyticus was isolated from 39 of 66 oyster samples and from 9 of 30 sediment and water samples. Isolation was most effective with prior enrichment of samples in trypticase soy broth with 7% NaCl and subsequent plating on thiosulfate citrate bile salts sucrose agar. V. parahaemolyticus was detected in only 1 of 8 refrigerated retail oyster samples. Aerobic plate counts at 25 C of refrigerated retail oysters were not much different from those of similar lots shucked under aseptic conditions in the laboratory (before shucking and washing in the plants). Aeromonas and Moraxella species were predominant in oysters at the retail level.
NEW WASTE WATER PRACTICES IN DAIRY PLANTS
Authors: Elliott Robert A.
Published: December 2016

Water pollution legislation is now having a national impact on pollution control activities in the Dairy Industry. The legislative programs that are being enforced are establishing uniform standards throughout the 50 states to abate pollution. It is apparent that individual plants will be forced to evaluate their present operation in terms of reducing waste water. The waste water from dairy plants presents certain characteristics which make treatment difficult. The wastes are produced over a short period during the day and this presents peak loads to a treatment facility. The strength of waste water will also vary. Rather than the dairy plant constructing its own treatment facility, the predominant means of disposal is to discharge to a municipal sewer system. For this method of treatment, certain charges are made against the dairy plant to pay for operation of the facility. These charges are becoming substantial, dollarwise, because of the high strengths and volumes of waste water being treated daily. By collecting product/water rinsings from the HTST and CIP system waste water loads can be reduced. Further equipment augmentation to existing CIP systems results in additional reduction in daily water usage.
A SCREENING MEDIUM AND METHOD TO DETECT SEVERAL MYCOTOXINS IN MOLD CULTURES1
Authors: Bullerman L. B.
Published: December 2016

A single culture medium consisting of rice powder (5%), corn steep liquor (4%), and agar (2%) was tested as a substrate for mycotoxin production using 34 known toxinogenic mold strains. Aflatoxins, ochratoxin A, sterigmatocystin, penicillic acid, patulin, citrinin, and zearalenone were each detectable in 4 days of incubation at 25 C using this medium. Extraction of melted agar cultures, in screw cap test tubes, with hot chloroform (55 C) followed by cooling to resolidify the agar greatly facilitated and simplified the extraction process and eliminated the need for separatory funnels. Mycotoxins were detected by treating developed thin-layer chromatographic plates with ammonia fumes, p-anisaldehyde, and phenylhydrazine and then viewing the chromatoplates under ultraviolet and white lights.
CHARACTERISTICS OF CHEDDAR CHEESE COOLED AT DIFFERENT RATES DURING EARLY CURING STAGES
Authors: Miah A. H. , Reinbold G. W. , Hartley J. C. , Vedamuthu E. R. , Hammond E. G.
Published: December 2016

Sixteen lots of Cheddar cheese were made from manufacturing-grade and grade-A milk by using commercial starters and cultures reported to give fruity and bitter-flavored cheese. Curd blocks were pressed for 4 and 20 h, then cooled to 7.5 C in brine or in air. There were no statistically significant differences in total, enterococcus, and Violet red bile agar counts, or proteolysis and judging scores among different pressing or cooling treatments. Significantly greater amounts of lactose, glucose, and galactose were present in brine-cooled cheese. Lactose persisted beyond 3 months. Air-cooled cheese had a significantly higher lactic-acid content, more free fatty acids, and more color variation. Air-cooled cheese was more severely criticized for flavor defects. Brine cooling produced uniform flavor, body, and color, and six of the seven judges preferred brine-cooled cheese.
BEHAVIOR OF CLOSTRIDIUM PERFRINGENS IN PRECOOKED CHILLED GROUND BEEF GRAVY DURING COOLING, HOLDING, AND REHEATING1
Authors: Tuomi S. , Matthews M. E. , Marth E. H.
Published: December 2016

The suitability of handling practices used in school kitchens was evaluated using ground beef gravy that was contaminated with Clostridium perfringens. Cooked gravy was cooled to 110 F (43.5 C) and inoculated with a mixture of vegetative cells and spores of C. perfringens NCTC 8239 to provide approximately 10,000 organisms/g. After inoculation, gravy was packed in bags, refrigerated for 16 h, held for 5 h at 82 F (28 C) or 42 F (5.5 C), and then heated in a compartment steamer for 35 min or until the temperature of the gravy at the center of the pan reached 165 F (74 C). C. perfringens was enumerated at intervals during cooling, holding, and heating of the gravy. The number of viable cells after 16 h of refrigeration at 42 F (5.5 C) was influenced by the first 6 h of cooling when the temperature of the gravy was in the range that permitted growth of C. perfringens (65–122 F; 18.5–50 C). Plate counts of gravy held for 5 h at 82 F (28 C) or 42 F (5.5 C) indicated stablization of the C. perfringens population. When 165 F (74 C) was the final temperature to which the gravy was heated, no viable cells of C. perfringens were found.
UTILIZATION OF FISH OIL BY CANDIDA LIPOLYTICA AND GEOTRICHUM CANDIDUM
Authors: Hottinger H. H. , Richardson T. , Amundson C. H. , Stuiber D. A.
Published: December 2016

Attempts were made to maximize biomass production in the oxidation of fish oil by Candida lipolytica Y1094 and Geotrichum candidum Y552 in shake flasks. Maximum biomass was produced on 5% w/v oil in water containing 1.5% (NH4)2 SO4, 2.2% KH2PO4, 0.12% MgSO4, 0.03% fish stickwater solids, 10 ppm FeSO4 · 7H2O, 1.5 ppm MnSO4 · H2O, and adjusted to pH 7.5. For G. candidum 40 ppb biotin were added to the medium. When inoculum size was varied from 1 to 8% v/v, the most appropriate inoculum size was about 2%. Aeration rates were increased by decreasing the medium volume per 500-ml shake flask. Maximum yields were obtained with 25 ml of medium. Cell recoveries were complicated by formation of oil-media emulsions. Several methods of biomass recovery were studied. Warming the acidified cell suspension in the presence of Triton X-100 allowed removal of oil from the cell mass. Extraction of the dried cell mass with ethyl ether yielded highest recovery of cell material compared to other methods. Dry cells contained 40.1 to 49.3% crude protein. These studies suggest the feasibility of obtaining 800 g of single cell biomass with a crude protein yield of 320 g from 1 kg of fish oil using batch or continuous culture systems.
INHIBITION OF BACTERIA BY SOME VOLATILE AND NON-VOLATILE COMPOUNDS ASSOCIATED WITH MILK
Authors: Kulshrestha D. C. , Marth E. H.
Published: December 2016

Nutrient broth inoculated with Salmonella typhimurium was dispensed into epoxy-lined aerosol cans. Twenty-five volatile compounds were then individually added to the cans to yield or non-volatile compounds were then individually added to the cans to yield final concentrations of 1, 10, 100, and 1000 ppm of each compound. Compounds tested included fatty acids (formic, acetic, butyric, hexanoic, octanoic and decanoic), aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and glyoxal), ketones (acetone, 2-butanone, and diacetyl), amines (propyl and hexylamine), alcohols (furfurol and methanol), sulfur compounds (methylsulfide, methylsulfone, methanethiol, and ethanethiol), acetonitrile, chloroform, ether, and ethylenedichloride. Bacteria were enumerated at intervals during incubation at 37 C.

Shorter chain fatty acids generally inhibited S. typhimurium more than did longer chain acids. At 10 ppm formic acid was most effective of those tested and at 1 ppm fatty acids were generally not inhibitory. Formaldehyde and glyoxal were more inhibitory than acetaldehyde and propionaldehyde. Diacetyl was most effective of the three ketones tested. Low concentrations of acetone or 2-butaoone sometimes enhanced growth of S. typhimurium. Acetonitrile at all concentrations tested significantly inhibited S. typhimurium during the terminal stages of incubation. Ether (10 ppm), chloroform (10 ppm), ethylenedichloride (100 ppm), and methylsulfone (100 ppm) generally caused significant reduction in growth of S. typhimurium. Ethanethiol was more detrimental to growth of S. typhimurium than were methylsulfide or methanethiol; amines were more inhibitory than alcohols.
LOSS OF ASCORBIC ACID FROM GRAPEFRUIT JUICE WHEN CULTURED WITH ASPERGILLUS PARASITICUS1
Authors: Alderman G. G. , Marth E. H.
Published: December 2016

Ascorbic acid was added to single-strength grapefruit juice that was then inoculated with Aspergillus parasiticus. Up to approximately 9.8 mg ascorbic acid/ml juice failed to inhibit either growth or aflatoxin synthesis by the mold. Loss of ascorbic acid during 18 days at 28 C was greater from inoculated than from uninoculated grapefruit juice that initially contained about 20 times the normal amount of the vitamin.
TEMPERATURE PROFILES DURING COMMERCIAL PASTEURIZATION OF MEAT FROM THE BLUE CRAB
Authors: Dickerson R. W. , Berry M. R.
Published: December 2016

Crab meat is pasteurized to inactivate most of the spoilage microorganisms, thereby extending its shelf life under refrigeration, but the process is not intended to achieve commercial sterility. As a first step in determining if spores of Clostridium botulinum would survive the process, crab meat temperatures were measured during commercial pasteurization. Tests were done in commercial establishments in Florida, South Carolina, North Carolina, Virginia, and Maryland. Cans of crab meat were instrumented with thermocouples, and heating curves were recorded during normal commercial processing. Water bath temperatures were reasonably constant among the different processors, ranging from 186 to 189 F. Holding times were more variable and ranged from 92 to 150 min. Lethality of the lowest thermal process was estimated to be equivalent to 18 min at 180 F.
STATUS OF THE RADAPPERTIZATION OF MEATS1
Authors: Rowley D. B. , Anellis Abe , Wierbicki E. , Baker A. W.
Published: December 2016

Considerable progress has been made toward development of highly acceptable radappertized meats through application of a heat treatment to an internal temperature of 65–80 C to inactivate proteolytic enzymes before irradiation, low temperature (−30 ± 10 C) of the food during irradiation, and addition of low levels of tripolyphosphate and sodium chloride. To assure that radappertized meats are free of potential pathogens and spoilage microorganisms they are given a minimum radiation dose (MRD) computed to effect a 12 log cycle reduction in the most radiation resistant strains of Clostridium botulinum spores. Inoculated pack studies are carried out to obtain the specific microbiological data required for computing the MRD. Cured meats normally have a lower MRD than uncured meats. In model systems concentrations of sodium chloride (NaCl) up to 4.0% (w/v) present during irradiation had no effect on radiation resistance, but NaCl did inhibit recovery of irradiated spores. A mixture of salts (4.0% NaCl, 30 ppm NaNO2 500 ppm NaNO3) had essentially the same effect as NaCl alone. Of 11 genera of vegetative cells examined, Micrococcs radiodurans and Streptococcus faecium were shown to be the most resistant to low-temperature gamma irradiation. Before the radappertization process can be established commercially it is necessary to provide proof that products so treated are safe for human consumption. An intensive animal feeding study of radappertized (4.7–7.1 Mrads) beef was initiated in 1971 and is expected to be completed in 1976.
MICROBIOLOGY OF WYOMING BIG GAME MEAT1
Authors: Smith F. C. , Field R. A. , Adams J. C.
Published: December 2016

Total bacteria present on antelope, mule deer, and elk carcasses and in ground meat from these carcasses were determined. In addition to total aerobic plate counts, counts for coliforms, fecal coliforms, coagulase-positive staphylococci, and Salmonella spp. were made. Average total aerobic plate counts of ground game ranged from 0.7 to 53 million organisms per gram. Surface swabs showed the bacterial counts to increase greatly during the 2-week aging period. Large numbers of coliforms and fecal coliforms were found in game meat. Nevertheless, game meat contained very few coagulase-positive staphylococci and no Salmonella spp. were detected.
MICROBIAL BETA-GALACTOSIDASE: A SURVEY FOR NEUTRAL pH OPTIMUM ENZYMES
Authors: Blankenship L. C. , Wells P. A.
Published: December 2016

Pure cultures of yeast, molds, and bacteria were screened for neutral pH optimum β-galactosidases (lactases) that would be suitable in dairy products applications. Only 2 of 125 identified and 10 of 250 unidentified cultures warranted further study. These cultures produced high levels of β-galactosidase with moderate galactose product inhibition. Characterization of the partially purified enzymes from unidentified cultures revealed that all required either Na+, K+ or Mg++ cation activation, were inhibited by Cu+ +, Mn+ +, and Fe+ + +, were most active around pH 6.8, and were unstable during storage (at either – 196 C or 4 C) except in the presence of 0.5 m ammonium sulfate. Most of the enzymes compared favorably in performance with a commercially available β-galactosidase when tested in skim milk.
USE OF ACETIC AND LACTIC ACID TO CONTROL THE QUANTITY OF MICROORGANISMS ON LAMB CARCASSES1
Authors: Ockerman H. W. , Borton R. J. , Cahill V. R. , Parrett N. A. , Hoffman H. D.
Published: December 2016

Numbers of bacteria were significantly (statistically) reduced on ovine carcasses, refrigerated for 12 days, by spraying with a solution of acetic or lactic acid. However the biological significance of this small reduction is of questionable value when good storage conditions are maintained.
WINE RESEARCH AT THE NEW YORK STATE AGRICULTURAL EXPERIMENT STATION1
Authors: Robinson Willard B.
Published: December 2016

The New York State Agricultural Experiment Station is uniquely qualified for an effective wine research program by its departmentmental structure and facilities. Cooperative research carried out by geneticists, viticulturists, entomologists, pathologists, and enologists is directed toward developing and selecting grape varieties for New York that will be suitable to the climate, resistant to pests, productive, and yield a high quality wine. The relation of vineyard site selection, cultural practices, and wine making techniques to wine quality are also under study. Enological research is the responsibility of chemists, microbiologists, and engineers who are studying the relation of wine composition, fermentaton, and processing methods to wine quality. An outstanding variety for white wine was introduced in 1972. Under the selection number GW-3, the new variety, named Geneva White, has gained wide acceptance in preliminary tests by growers and wine makers. Promising new red varieties for New York are also under development at the Geneva Experiment Station.
A HOT ACID TREATMENT FOR ELIMINATING SALMONELLA FROM CHICKEN MEAT
Authors: Juven B. J. , Cox N. A. , Mercuri A. J. , Thompson J. E.
Published: December 2016

Hot succinic acid was tested for destruction of Salmonella on chicken broilers. Immersion in a 3% succinic acid solution at 60 C resulted in some destruction of Salmonella montevideo (200 cells inoculated per leg), but an acid treatment at 85 C for 2–3 min was required to achieve elimination. However, when 200 cells of S. montevideo were inoculated into either a chicken meat or skin homogenate a temperature of only 60 C for 1 and 2 min, respectively, was required for elimination.
CHANGES IN MILK, WHEY, AND BLUE CHEESE AS INDUCED BY BENZOYL PEROXIDE1,2
Authors: Washam C. J. , Reinbold G. W. , Vedamuthu E. R. , Jorgensen R.
Published: December 2016

Milk proteins were subjected to treatment with various levels of benzoyl peroxide, with and without heating at 60 C for 2 h. Heating had a pronounced effect on whey proteins, but polyacrylamide gel electrophoresis revealed changes in proteins not attributable to heat alone. The effect on proteins was reflected in an increased tendency for the benzoyl peroxide-heat treated cheeses to expel moisture during leakage tests. Use of 17.8 ppm benzoyl peroxide resulted in a markedly whiter cheese than that made using 5.9 ppm and reflectance studies indicated this to be true even when no heat treatment accompanied the benzoyl peroxide. Use of benzoyl peroxide in the bleaching process did not decrease mold development in ripening loaves nor was acid production by lactic cultures diminished. In addition, proteolysis of milk proteins by rennet was not reduced by the presence of benzoyl peroxide.
EXPERIMENTAL PRODUCTION OF AFLATOXIN IN CITRUS JUICE AND PEEL1
Authors: Alderman G. G. , Marth E. H.
Published: December 2016

Grapefruit juice and grapefruit peel each supported growth of and aflatoxin formation by Aspergillus parasiticus and Aspergillus flavus. Grapefruit peel was a better substrate than grapefruit juice for toxin production; amounts of aflatoxin B1 and G1 were 5–10 times higher in the peel when the same mold strain grew at 28 C in both substrates for up to 62 days. In juice, amounts of aflatoxins B1 and G1 produced by A. flavus markedly decreased after 18 days and then became stabilized, whereas amounts of aflatoxin G1 formed by A. parasiticus increased to 34 days then declined and stabilized. When the molds grew on grapefruit peel, amounts of aflatoxins B1 and G1 produced increased for 38 days (A. flavus) and 26 days (A. flavus and A. parasiticus), and then declined and became stabilized. Amounts of aflatoxin B1 (A. parasiticus) increased rapidly early during incubation and then remained relatively constant through an extended holding time. Concentrations of aflatoxins B2 and G2 formed by both molds in each substrate did rot significantly change during extended incubation. A. parasiticus grew in grapefruit juice for 14 days at 28 C after which the juice was separated into three fractions. The solids fraction contained 72.8%, mold 16.9%, and filtrate 10.3% of the total amount of aflatoxin produced. Similar results were obtained with lemon and orange juice. Frozen storage (−18 C) of grapefruit juice samples containing aflatoxin did not significantly affect the amount of aflatoxin recovered until after 18 weeks.
STAPHYLOCOCCUS AUREUS IN COMMERCIALLY PROCESSED FLUID DAIRY AND NON-DAIRY PRODUCTS1
Authors: Sheikh M. I. , Luedecke L. O.
Published: December 2016

Eight coagulase-positive staphylococci were isolated from 165 samples of commercially processed fluid dairy products and non-dairy whip. Seven of eight isolates tested for enterotoxigenicity by the mioroslide gel diffusion method did not produce enterotoxin A, B, or C, whereas one isolate produced enterotoxin C. None of the 8 isolates survived heating at 62.8 C for 30 min in raw low-count milk or in sterile milk.
EFFECT OF LOW DOSE GAMMA IRRADIATION ON GROWTH AND AFLATOXIN PRODUCTION BY ASPERGILLUS PARASITICUS1
Authors: Bullerman L. B. , Hartung T. E.
Published: December 2016

Spores and growing vegetative mycelia of Aspergillus parasiticus strains NRRL 2999 and NRRL 3000 were irradiated at 100 and 200 Krad, and the effects on growth and aflatoxin production in yeast-extract sucrose (YES) broth were measured. Irradiation of growing mycelia reduced subsequent growth in YES broth by a greater amount than irradiation of spores. Irradiation of spores at 100 Krad resulted in more B1 and G1 production by strain NRRL 2999 than the non-irradiated control, however, strain NRRL 3000 produced less aflatoxins B1 and G1 after irradiation at 100 Krad than its non-irradiated control. Spores of both strains irradiated at 200 Krad produced less aflatoxins B1 and G1 than non-irradiated controls. Irradiation of growing vegetative mycelia of both strains at 100 and 200 Krad resulted in a definite decline in both aflatoxins B1 and G1 in subsequent cultures at each irradiation level. Apparent stimulation of production of both B1 and G1 occurred after irradiation of spores of strain NRRL 2999 at 100 Krad. However, the variation of the values as determined by the standard deviation was such that one would conclude that no differences existed among means. The apparent stimulation was slight and of much less magnitude than that which has been reported by other investigators using A. flavus. No stimulation of toxin production was observed with the other strain when grown from irradiated spores or with either strain when vegetative mycelia were irradiated.
A STATISTICAL EVALUATION OF THE 3M BRAND AUTOMATIC COLONY COUNTER1,2
Authors: Packard V. S. , Ginn Roy E.
Published: December 2016

The 3M Brand Automatic Colony Counter, Model 620, was evaluated and compared with three laboratory technicians on raw milk Standard Plate Count (SPC) cultures over the range of counts from 0–300 colonies per culture plate. Overall, the estimated total variance for the three technicians was 15.07, for the 3M unit 17.82. On plates averaging greater than 150 colonies the 3M unit and hand counts were about equal in Variability. On lower counts the 3M device was somewhat more variable, although within what would appear to be acceptable limits. For the range of data studied, 99.4% of the variance (for the average of three counts by either method) could be accounted for by a similar average of observations using the other method. The 3M unit averaged 2.33 counts higher than technician counts.
INFLUENCE OF THE HARVEST METHOD ON CONTAMINATION OF FRUIT BY BYSSOCHLAMYS ASCOSPORES
Authors: Splittstoesser D. F. , Downing D. L. , Roger N. F. , Murdock D. I.
Published: December 2016

Mechanically-harvested tart cherries and Concord grapes were not more heavily contaminated with Byssochlamys ascospores than were hand-picked fruit. The data suggested, however, that both harvest procedures may be sources of contamination, probably because of soiled surfaces. Studies on various Byssochlamys isolates revealed marked differences in heat resistance.
UTILIZATION OF FISH OIL BY CANDIDA LIPOLYTICA AND GEOTRICHUM CANDIDUM
Authors: Hottinger H. H. , Richardson T. , Amundson C. H. , Stuiber D. A.
Published: December 2016

Oil from alewife (Alosa pseudoharingus) was oxidized in shake flasks by Candida lipolytica Y1094 and Geotrichum candidum Y552. Utilization of alewife oil in a basal medium indicated that fish stickwater was as effective a growth supplement as yeast extract or cornsteep liquor. Maximum cell yields of both organisms were obtained when the starting pH was between 7.5–8.2. Nitrogen uptake per gram of cells for both microorganisms was relatively greater during the first 11 h of oil oxidation and declined thereafter. Fish oil concentrations in the basic medium were varied between 0.5 to 10% w/v. The increase in cell yield essentially stopped for both organisms at the 5% oil level. With 5 to 10% oil pH values of media decreased below the optimal range after 22 h without significantly more cell production than in media with 1.0 and 2.5% oil. After 33 h pH values of the media with high oil concentrations decreased to a level where growth was inhibited.
CHARACTERIZATION OF TENACIOUS RESIDUE OF ALKALINE CIRCULATION CLEANING1
Authors: Maxcy R. B. , Arnold R. G.
Published: December 2016

Circulation cleaning presents many opportunities for advancement in liquid food handling systems, but the effectiveness commonly must be evaluated by means other than visual inspection. To study this problem of evaluation, a laboratory system was developed to simulate the soiling and cleaning process of a commercial high-temperature short-time pasteurizer unit. Proof of similarity was obtained by determining quantity of soil at various cleaning intervals and through qualitative examination of the soil with thin-layer chromatography, gas liquid chromatography, and infrared spectroscopy. Lipoidal materials were found to be most resistant to alkaline cleaning. Material removed near the end of the cleaning cycle and material removed by ether rinse of the equipment after the cleaning cycle were similar to milkfat in the milk used for soiling and to the residues recovered from early intervals of cleaning. The removal process for lipoidal material was not attributable to saponification, because little saponification occurred with temperature and alkali concentration associated with circulation cleaning. Data in this paper indicated directions for further work toward criteria of cleaning efficiency and effectiveness.
Ultra-Pasteurization of Whipping Cream
Authors: AGGARWAL M. L.
Published: December 2016

Ultra-pasteurization of whipping cream in the United States is now synonymous with commercial sterilization. Correct composition of whipping cream is essential to comply with the standard of identity and to produce a product with desirable qualities. Careful selection of the ultra-high-temperature (UHT) processing system is helpful to offset unwanted characteristics in the finished product. Functionality of various stabilizers and emulsifiers in the product is described. Homogenization of the product during UHT processing helps improve its physical stability. A long shelflife whipping cream with improved physico-chemical stability but containing no foreign additives can be produced commercially. Some of the physical conditions for whipping cream such as its cold storage, whipping time, and temperature are necessary to assure consumers of its peak performance.
Impact of Vegetable Proteins on Dairy Products
Authors: JONAS JOHN J.
Published: December 2016

The technological status of research trends directed toward creation of dairy product analogues based fully or partially on vegetable protein raw materials is reviewed. Particular emphasis is given to soya protein based milk and cheese analogues. Nutritional and organoleptic properties of the analogues are critically discussed. Continued research activity is required by product developers to reach consumer satisfaction, nutritional adequacy, and legal approval for milk and cheese analogue products.
Comparative and Collaborative Studies on the Preparation of Hard Cheese Samples for Microbiological Assay Using a Plastic Pouch Technique
Authors: WILKINSON R. F. , RICHARDSON G. H.
Published: December 2016

Hard and very hard cheese samples were prepared for microbiological examination by emulsification with sodium citrate solution in a polyethylene plastic pouch. Results were comparable to those obtained using a standard blender technique.
Survival of Enteric Viruses on Fresh Fruit
Authors: KONOWALCHUK JACK , SPEIRS JOAN I.
Published: December 2016

Several enteric viruses were examined for their survival at 4 C on strawberries, cherries, and peaches. With few exceptions, recovery of virus from fruit maintained in a humid atmosphere decreased with time; recoveries from strawberries were especially low; recoveries of coxsackievirus and echovirus were greater than those of poliovirus and reovirus. Aqueous fruit infusions were antiviral and in general correlated with virus loss on the fruit surfaces. An infusion prepared from intact grapes inactivated poliovirus. Desiccation was another contributing factor in virus destruction. No naturally-occurring virus was found in nine fruit samples examined in this study.
Some Volatile and Nonvolatile Compounds Associated with Milk and Their Effects on Certain Bacteria. A Review1
Authors: KULSHRESTHA D. C. , MARTH E. H.
Published: December 2016

Raw and heated milks contain numerous volatile and other compounds. This review discusses some of the available information with particular emphasis on compounds having a low boiling point and which are likely to be removed by the vacuum treatment that often is combined with commercial pasteurization of milk. Reports dealing with carbonyl compounds including fatty acids, alcohols, and ketones have been reviewed. Emphasis has been given to fatty acids having up to 10 carbon atoms. Sections dealing with the occurrence in milk of volatile sulfur compounds, nitrogenous compounds, and alcohols also are included. A brief discussion about some miscellaneous compounds concludes the first part of this review. A detailed discussion of the effects of some compounds associated with milk on certain bacteria constitutes the second part of this review. The inhibitory effect of fatty acids, aldehydes, ketones, sulfur compounds, amines, alcohols, and some other compounds on lactic streptococci, lactobacilli. Escherichia coli. Salmonella typhimurium, Staphylococcus aureus and some other organisms encountered in the dairy industry, is discussed.
Further Studies on a Growth Medium for Lactobacillus sanfrancisco
Authors: SUGIHARA T. FRANK , KLINE LEO
Published: December 2016

The medium developed for the original isolation studies on Lactobacillus sanfrancisco has been further refined to provide a basis for development of media for commercial preparation of cell concentrates. Addition of salts, purines, pyrimidines, and optimization of casein hydrolysate and Tween 801 levels resulted in markedly improved growth but did not eliminate the need for freshly prepared yeast extractives (FYE). Commercial yeast, liver, corn steep, and protein hydrolysate preparations tested were inadequate substitutes for the FYE. High maltose levels appear to stabilize viable counts over longer incubation periods. Some differences between strains in growth requirements were observed. Strains L and T were the least fastidious nutritionally, appeared indifferent to oxygen, and had a minimal requirement for Tween 80, but a primary requirement for purines-pyrimidines. Strains B and C were inhibited by oxygen and had a primary requirement for trace element supplementation and Tween 80. Strain L which showed the most rapid and heaviest growth has been selected as the type strain and the one to be utilized in initial commercial tests as a starter culture preparation.
Thermal Inactivation of Conidia From Aspergillus flavus and Aspergillus parasiticus
Authors: DOYLE M. P. , MARTH E. H.
Published: December 2016

Thermal resistance at 45, 50, 55, and 60 C of conidia from various strains of Aspergillus flavus and Aspergillus parasiticus was determined using a heating menstruum buffered at pH 7.0 with KH2PO4-NaOH. Heat resistance of conidia from both molds was strain-dependent. With moist heat at 45 C, D-values for conidia from various strains ranged from 14 to >161 h, whereas at 60 C the range was from 8 to 59 sec. At 50 and 55 C, D values ranged from 16 to 987 and 3 to 29 min, respectively. There appeared to be a positive relationship between the degree of heat resistance of conidia and the amount of aflatoxin produced by the different aspergilli. Conidia that were 15 and 20 days old were less resistant to heat than when they were 7 or 10 days old. Conidia that were produced on a substrate low in protein and high in glucose were more heat resistant than were those produced on a more proteinaceous substrate that contained little glucose.
Temperature Control
Authors: BODYFELT F. W. , DAVIDSON W. D.
Published: December 2016

Temperatures of perishable dairy products in 30 Oregon retail food stores were determined systematically with the aid of a quick response electronic thermometer. Sensitive thermistor surface probes permitted measurement of product temperatures from the exterior surfaces of two adjacent containers to within 0.5 F. A switch box facilitated the simultaneous use of up to six probes for measuring product, air blower, and air “curtain” temperatures at various cabinet shelf locations. Fluid milk temperatures for the outside rows of shelves averaged 4.5 F higher than the inside rows of product. The average temperatures for products in refrigerated display cases were: fluid milk and cream, 43.9 F; cottage cheese, 46.4 F; and hard cheese, 48.8 F. More than 35% of all products checked exceeded the Oregon maximum legal temperature of 45 F and 75% of the products exceeded the generally accepted optimum storage temperature of 40 F. The data indicate a definite need for improvement in temperature control of refrigerated display cases used for perishable dairy products. A form was designed to simplify and efficiently record temperature data for retail food stores.
Fungi in Foods
Authors: KOBURGER J. A. , NORDEN A. R.
Published: December 2016

It was possible to compare recovery of yeasts and molds from 30 food samples by three methods, employing plate count agar and broth with added antibiotics. Although the pour plate and surface plate methods gave comparable results, the Most Probable Number (MPN) procedure consistently yielded the highest counts. With some of the samples, the MPN method was the only one in which recovery occurred. It thus appears that this procedure is practical for detection of fungi and may be of use in survey work or when analyzing foods containing low numbers of microorganisms.
Bacteriological Quality of Selected Delicatessen Foods
Authors: HARRIS NATHOLYN D. , MARTIN STEPHEN R. , ELLIAS LORETTA
Published: December 2016

Warm and cold delicatessen foods were purchased from local retail stores and were subsequently analyzed for total plate counts, Staphylococcus aureus and coagulase positive staphylococci, Clostridium perfringens, and coliforms. Foods were analyzed immediately after purchase, after holding 3 h at 37 C, and after holding at 9 C for 4 days. The total viable bacteria, staphylococci, coliform, and C. perfringens numbers did not vary much during storage at 37 C for 3 h and 4 days at 9 C. The average total count was 350,000 cells per gram for all foods examined. More than 30% of the staphylococcal colonies tested were coagulase positive. Meat salads contained the highest total counts and warm meats contained the lowest numbers of cells.
Effect of Chemically Adjusted Meat pH and Drying Air Velocity on some Properties of Dry Sausage
Authors: TOWNSEND W. E. , DAVIS C. E. , MERCURI A. J.
Published: December 2016

Effects of chemically adjusted meat pH (lowered by calcium chloride; raised by sodium hydroxide-sodium citrate), and velocity of air during drying on some properties of a dry type sausage were investigated. During the first 2 days of drying, sausages having initial pH values of 5.5 had a more intense cured meat color than those having initial pH values of 5.9 or 6.6. During 21 days of drying. pH 5.5 sausages showed very little change in shape, while sausages with pH values of 5.9 and 6.6 exhibited triangular and twisted triangular cross-sectional shapes. respectively. Sausages having initial pH values of 5.5 and dried with high air velocity had poor internal cured meat color and texture and developed hollow centers, but not in those having pH values of 5.5, 5.9, or 6.6 and dried with low air velocity. Peelability improved during drying.
The “New Disease” Status of Human Anisakiasis and North American Cases: A Review1
Authors: JACKSON G. J.
Published: December 2016

The first confirmed case of human anisakiasis, i.e., infection with larval anisakine nematodes, occurred in 1955. The practice of holding fish refrigerated for relatively long periods before gibbing and curing, thus enabling larger numbers of anisakine larvae to move from the viscera into edible portions, as well as the increased popularity of raw and semi-raw fish recipes may partially explain the new awareness of human anisakiasis. However, it is probaly not a totally new disease. Presumptive cases are mentioned in the literature as early as 1867. Other cases may have been misdiagnosed because anisakine larvae resemble ascarid larvae in general morphology. To date, Japan (“several hundred cases”) and the Netherlands (about 160 cases) have reported the largest number of human infections. Six confirmed cases have been reported from North America. Human infections are acquired from consumption of raw, underheated, insufficiently frozen or lightly marinated fish dishes. The contained anisakine larvae (presumably belonging to genera such as Anisakis, Phocanema, Porrocaecum, and Contracaecum whose final hosts are mammals or birds) do not mature in humans but can survive long enough to cause pathology. Anisakine larvae remaining free or attached in the human digestive tract may cause irritation, severe inflammation, and ulceration; sometimes the larvae are expelled by coughing or vomiting. Anisakine larvae that penetrate totally into the tissues may stimulate a granuloma formation that surrounds and is thought to kill them. The world incidence of human anisakiasis is just being discovered. Surveys, improved criteria and methods for identifying larval anisakines, and establishment of experimental hosts and culture systems that are practical in the laboratory are needed to determine the extent of infected seafood and to prevent, diagnose correctly, and treat human infections.
Enteroviruses and Potential Bacterial Indicators in Gulf Coast Oysters
Authors: FUGATE K. J. , CLIVER D. O. , HATCH M. T.
Published: December 2016

Bacteriological and virological examinations of Louisiana and Texas Gulf Coast oysters were done over a 12-month period. Oysters taken from approved waters sometimes contained detectable enteroviruses: echovirus 4 and poliovirus 1 were in one each of 17 samples from Texas, and poliovirus 3 was in one of 24 samples from Louisiana. Neither the coliform MPN for the water from the shellfish beds nor the coliform MPN, Escherichia coli MPN, or aerobic plate counts for the shellfish meats was clearly indicative of the presence of virus. Two of the 24 oyster meat samples which contatined Vibrio parahaemolyticus also yielded virus; however, virus was present in one of 17 samples in which V. parahaemolyticus was not detected. Poliovirus 1 was also found in frozen, shucked oysters imported from Japan.
Microbiological Safety and Palatability of Selected Vended Burgers
Authors: MUELLER DONNA C.
Published: December 2016

A total of 52 vended burgers from two vendors were assayed for total aerobic plate counts, coliforms, coagulase-positive staphylococci, salmonellae, and Clostridium perfringens. During the first year burgers were obtained from a single vendor, while in the second year two vendors' products were included. Palatability scores were obtained only in the second year of the study. Mean total aerobic plate counts ranged from the high value of 31 × 104 per gram for burgers as obtained to a low value of 84 × 102 per gram after reheating. Only four samples (three as obtained) contained coliforms in low numbers and no coagulase-positive staphylococci were detected. Only five samples were presumptive for salmonelae, and Clostridium perfringens was detected in very low numbers when present. It was concluded that these foods were microbiologically safe to consume but that there was a need for product improvement since taste panel ratings for general desirability ranged from fair to poor.
Histamine and Tyramine Content of Meat Products
Authors: RICE S. , EITENMILLER R. R. , KOEHLER P. E.
Published: December 2016

A survey was conducted to determine the histamine and tyramine contents of a variety of meat products. Histamine was found in all products at concentrations only slightly greater than one would expect from normal physiological amounts found in muscle. Semi-dry sausage products contained an average histamine concentration of 3.59 μg/g compared to an average of 2.87 μg/g in dry sausages. Country-cured hams averaged 1.69 μg histamine/g. Emulsion type products contained slightly less histamine than the fermented sausages. Braunschweiger, an exception, contained 3.6 μg histamine/g but would be expected to contain more histamine than other emulsion-type products because of its liver content. Data indicate that histamine is not formed to an appreciable extent in these meat products under normal processing conditions.

Detectable amounts of tyramine were found in 71% of the sausages and in 39% of semi-dry sausages. Tyramine was not detected in country-cured ham. Average tyramine concentrations were 244 and 85.8 μg/g in the dry and semi-dry sausages, respectively. The greatest tyramine concentration found in this study was 1237 μg/g in a Genoa salami. It is apparent that sufficient tyramine can occur in ripened sausages to be troublesome to tyramine-susceptible individuals.
A Comparison of Phosphate Buffered and Distilled Water Dilution Blanks for the Standard Plate Count of Raw-Milk Bacteria1
Authors: HUHTANEN C. N. , BRAZIS A. R. , ARLEDGE W. L. , DONNELLY C. B. , GINN R. E. , RANDOLPH H. E. , KOCH E. J.
Published: December 2016

Raw milk samples were diluted with distilled water or distilled water with added phosphate buffer as recommended by Standard Methods for the Examination of Dairy Products. The standard plate counts were higher in diluent without phosphate buffer with both high and low count milk. The higher counts were significant when analyzed by a nonparametric sign test or a t-test of differences but were not significant with an analysis of variance technique. Reproducibility was not statistically different in the two diluents. It is suggested that the use of phosphate buffer for raw milk bacteria counts be discontinued until information showing definite advantages is provided.
Temperature Equilibration Times of Plate Count Agar and a Comparison of 50 Versus 45 C for Recovery of Raw-Milk Bacteria1
Authors: HUHTANEN C. N. , BRAZIS A. R. , ARLEDGE W. L. , DONNELLY C. B. , GINN R. E. , RANDOLPH H. E. , KOCH E. J.
Published: December 2016

Sixty raw milk samples were plated using “Standard Methods” agar tempered to 45 or 50 ± 1 C. The standard plate count was significantly lower with the agar at 50 C. Tempering time (to 44–46 C) of a flask of agar in a water bath was about 5–10 min longer than that of a comparable flask of water. Time required to reach the desired temperature depended upon the volume of agar in the flasks, the number of flasks, and the volume of the water in the bath. Up to an hour of equilibration time may be necessary for newly autoclaved agar to reach the recommended temperature (44–46 C). Insufficient tempering time might cause an excessively high plating agar temperature which might cause a reduction in bacterial counts, especially of a heat sensitive psychrotrophic bacterium.
Bacteriological Quality of Delicatessen Foods: Are Standards Needed?
Authors: PACE PAUL J.
Published: December 2016

Surveillance of seven types of delicatessen salads (chicken, egg, ham, macaroni, American potato, shrimp, and tuna) was conducted from March through July, 1974. Liver spread and sandwich spread were included in the sampling. Products were obtained from approximately 150 retail establishments. A separate surveillance of one central production unit and approximately 18 retail establishments, which it supplied, was also conducted. Twenty six percent to 85% of samples of products obtained from general retail outlets had aerobic plate count (APC) values of less than 100,000 per gram. Thirty six percent to 79% had coliform Most Probable Number (MPN) levels of less than 100 per gram, while 83 to 100% contained less than 10 Escherichia coli per gram. Some samples of each of the products contained low numbers of coagulase-positive staphylococci. Seventy one per cent to 96% of samples of various products, obtained from a central production unit, yielded APC values of less than 100,000 per gram. Forty five percent to 94% had coliform MPN values of less than 100 per gram. Two of six products contained low levels of coagulase-positive staphylococci in 9% and 2% of the samples examined.
Evaluation of Cultural Methods to Isolate Salmonella from Pressed Yeast and Dried Inactive Yeast
Authors: WILSON CLYDE R. , ANDREWS WALLACE H. , POELMA PAUL L.
Published: December 2016

An improved method recently developed to isolate Salmonella from dried active yeast was evaluated for use with pressed yeast and dried inactive yeast. The method for dried active yeast consists of pre-enriching a 25-g sample in trypticase soy (TS) broth at a sample-broth ratio of 1:10, incubating at 35 ± 0.5 C for 24 ± 2 h, and transferring to lauryl sulfate tryptose (LST) and tetrathionate (TT) broths. After 24 ± 2 h at 35 C, the broths are streaked to selective agars. When evaluated for use with pressed yeast, Salmonella attained higher most probable number levels/ml with this method (7.9 × 104 – 3.3 × 106), than with 1% tryptone broth and a sample-broth ratio of 1:5 (1.7 × 103 – 1.7 × 106), which is the current examination procedure for pressed yeast. Salmonella was consistently isolated from selective agars streaked from TT broth, but was seldom isolated from selective agars streaked from LST broth because of massive overgrowth by non-salmonellae. With dried inactive yeast, this modified method was equal to, but not significantly better than, pre-enrichment of the yeast in sterile distilled water at a sample-broth ratio of 1:5, which is the current procedure for dried inactive yeast.
Evaluation of a Proportionate Sampling Device to Collect Samples for Milkfat Analysis from Farm Bulk Milk Tanks1
Authors: SCOTT R. H. , GLASS E. D.
Published: December 2016

Samples of farm bulk tank milk for milkfat analysis were obtained by conventional methods (following 5–10 min of agitation) and, 2 to 3 h later, by means of a prototype vehicle-mounted proportionate sampler (maximum of 15 sec pre-agitation). Two preliminary series of proportionate samples (40 and 80 ml) were tested in duplicate for milkfat content and the mean of each sample compared with the mean milkfat content of the respective conventional sample. Ninety-seven percent and 98.1% (40- and 80-ml samples, respectively) of the paired comparisons were within ± 0.10% milkfat. Statistical analyses of both series of paired comparisons revealed that there was no significant difference between the mean milkfat content of proportionate and conventional samples, ie, the milkfat content of milk samples obtained by the proportionate sampling device accurately represented the milkfat content of milk samples obtained by the conventional method of sampling. An increase in volume of the proportionate sample from 40 to 80 ml did not significantly improve the representativeness of the proportionate sample.
Physico-Chemical Characteristics of Composite Flours
Authors: PULLE M. W. , INO K.
Published: December 2016

Physico-chemical parameters that influence dough attributes and baking quality were investigated in single and composite flours. Considerable variation in the starch and protein components was observed in the different formulations of wheat and substituent flours. Incorporation of kurakkan, sorghum, or manioc flour increased gelatinization temperature, viscosity, and amylose content irrespective of the extent of substitution. Although increases in amylose content were within tolerable limits, changes in gelatinization temperature and viscosity characteristics necessitate use of chemical agents and modified technology for preparation of acceptable products. A marked reduction in protein content was revealed in manioc-wheat composites, wherein nutritive fortification should comprise an additional requisite.
Ultra-Pasteurization of Egg Nog with Modern Processing and Packaging Equipment
Authors: AGGARWAL M. L.
Published: December 2016

A tubular indirect heat exchange ultra-high-temperature (UHT) processing system coupled with an aseptic packaging machine is described for successful commercial ultra-pasteurization of egg nog. Shelflife of the resultant product is extended manifold over conventionally pasteurized egg nog. Numerous formulations, using various milk ingredients, are presented to suit the geographical location of manufacturing plants, and availability of raw ingredients. Use of processing and packaging equipment in ultra-pasteurization of egg nog has no significant effect on its natural color, flavor, body and texture, and nutritive value.