bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional properties of porcine blood globin decolourized by different methods
Authors: Yang Jeng‐Huh , Lin Chin‐Wen 
Published: March 2003

The purpose of this study was to compare the functional properties of freeze‐dried porcine blood globin isolates, which were obtained after decolourization with sodium carboxymethylcellulose (Na‐CMC), acid‐acetone (A‐A), hydrogen peroxide (H2O2), or alcalase (an endopeptidase). Porcine red blood cell concentrates (RBCCs) without decolourization were freeze‐dried as controls. The proximate composition, solubility, emulsifying activity index, emulsifying stability, foaming capability, foam stability and gel strength of the globin isolates were determined. The solubility of the globin isolates was affected by decolourization treatment and pH (within the range 2–9). The globin isolates obtained by A‐A decolourization were particularly affected by pH. The solubility of the alcalase‐treated globin isolate was the highest of all the globin isolates, followed by the Na‐CMC‐ and H2O2‐treated globin isolates. The emulsifying activity index of A‐A‐treated globin isolate was unaffected by pH adjustment. The emulsifying stability of all isolates was not significantly different over the pH range 2–9. The foaming capacity was significantly different among treatments and pH levels (P < 0.01). The foaming capacity at pH 2–3 was greater than at pH 4–9, with the exception of the alcalase‐treated globin isolates. A‐A‐treated globin isolates had poor foaming capacity at pH 4 and 5, and foams produced at pH 8 and 9 from alcalase‐treated isolates had poor stability. The 10% solution of RBCCs (control) showed the greatest gel strength, followed by A‐A‐treated, Na‐CMC‐treated and H2O2‐treated globin isolates. The alcalase‐treated globin isolate solutions did not form gels. The decolourization methods surveyed in this study were all at least partially successful in ameliorating the dark‐brownish colour of RBCCs. However, the functional properties of the isolates, excluding gel strength, were generally comparable with those of RBCCs.
Bovine spongiform encephalopathy (BSE) – a review
Authors: Blanchfield J. Ralph 
Published: March 2003

Summary

Bovine spongiform encephalopathy (BSE) incidence. The number of new cases continues to fall as forecast (from the peak of 37 487 in 1992 to 13 825 in 1995, to 7406 in 1996 to 3980 in 1997) and is on track to bring the epidemic to an end.
BSE/nvCJD. Findings since 1996 indicate that the agents of BSE and new‐variant Creutzfeldt—Jakob disease (nvCJD) possess the same ‘fingerprint’. This is consistent with the transmission of BSE infection to humans. Although it remains possible that both BSE and nvCJD may have been triggered by some currently unknown cause, it is difficult to conceive what that might be.
nvCJD incidence. The UK Department of Health reported 24 cases of nvCJD up to the 6 April 1998. Assuming that nvCJD is the result of consumption of BSE infective materials before 1989, it is too soon to draw any conclusions about likely future incidence.
Infectivity of bovine materials. In its report dated 9 December 1997, the EU Scientific Steering Committee has set out the most up‐to‐date information and assessment of the infectivities of various bovine materials.
Beef, milk and bones. Assays in mice have not detected BSE infectivity in muscle meat (beef) or milk from confirmed cases. The more sensitive assay in calves is yet to be concluded, but to date results are negative. Thus, although low levels of infectivity cannot be excluded, the risk from beef or milk is currently considered to be extremely small. Calf experiments have detected infectivity in the dorsal root ganglia, the trigeminal ganglia and the bone marrow. The risk involved to people eating beef is extremely low, about one case of nvCJD in a billion years per person. However, this estimate has a wide range of uncertainty, and the UK government has responded by banning the sale of beef on the bone.
Galatin and tallow. In its report of 19–20 February 1998, the EU Scientific Steering Committee carried out risk assessments of various raw materials and production processes for gelatin and tallow, and has issued ‘scientific opinoins’ thereon.
Blood. Recent research on mice shows that the lymph system is involved in the passage of infectivity from gut to brain. This implicates the lymphoreticular system and suggests that circulating lymphocytes may carry infectivity. Infectivity has been found in the tonsils of nvCJD victims. Thus, the Spongiform Encephalopathy Advisory Committee (SEAC) has suggested the leucodepletion of blood supplies as a precaution.
Official Inquiry into BSE and CJD. The Institute of Food Sciecne and Technology (IFST) welcomed the official independent enquiry into BSE and has made a written submission.
Effects of meat piece size and phosphate on maximum slicing rate, cooking loss and sensory quality of a re‐formed pigmeat shoulder product
Authors: McDermott Martin , Mitchell Peter C. , Welch Robert W. 
Published: March 2003

Summary Two pre‐tumbling treatment variables (meat piece size; raw product phosphate content) were evaluated for their effects on maximum slicing rate (MSR), cooking loss and sensory quality of a commercially produced, cooked re‐formed pigmeat shoulder product. At 0.457% phosphate, incremental reductions in meat piece size which increased specific surface from 0.60 to 0.93 cm2 cm−3 enabled MSR to increase from 300 to 400 slices min−1, reduced cooking losses from 0.875 to 0.60% and gave a more tender product. At 0.60 cm2 cm−3 specific surface, increasing phosphate incrementally from 0.457 to 0.532% produced similar positive effects on MSR and cooking loss but at phosphate above 0.482% sensory quality declined. Combination of optimal specific surface (0.93 cm2 cm−3) and phosphate (0.482%) permitted a MSR of 420 slices min−1, reduced cooking loss to 0.50% and gave an acceptable product. These process modifications can thus be advocated for improved production rate, yield and sensory quality.
An ESR study on identification of gamma‐irradiated kiwi, papaya and tomato using fruit pulp
Authors: Jesus Edgar F. O. , Rossi Alexandre M. , Lopes Ricardo T. 
Published: March 2003

Summary In this work we use paramagnetic defects induced by radiation in the fruit pulp to identify gamma‐irradiated kiwi, papaya and tomato. Pulp without seed, peels or stalks are treated by alcoholic extraction in order to remove water, soluble fractions and solid residue. The ESR spectra of pulp samples of irradiated fruit is composed of species A (g = 2.0045) and species C (g = 2.0201 and g = 1.9851), which are also observed in irradiated stalks and skins. In comparison with samples which are not submitted to alcoholic extraction, species C is stable enough to be used as a dose marker. Furthermore, the species C signal can be detected perfectly even in pulp samples irradiated with doses as low as 200 Gy. Irradiation doses of fruit, exposed to 200–900 Gy of a gamma rays, were estimated with an overall uncertainty of 15% using dried pulp samples. These results indicate that radicals induced in pulp have potential to be used in the identification and absorbed dose determination of irradiated fruit.
Effects of boiling, warm‐holding, mashing and cooling on the levels of enzyme‐resistant potato starch
Authors: Gormley Ronan , Walshe Thomas 
Published: March 2003

Summary The effects of boiling, warm‐holding, cooling and mashing on the enzyme‐resistant starch (ERS) content of potatoes was studied together with inter‐tuber and inter‐cultivar variation in ERS content. Inter‐tuber variation in ERS content was small and mean values (on a dry matter basis) for boiled and raw potatoes were 10.7 and 74.2% (cultivar Rooster) and 10.8 and 74.3% (cultivar Anna). There was no significant difference between the ERS values of boiled potatoes of seven cultivars (range 10.0–10.8%). Warm‐holding mashed potatoes at 65–70 °C for 1 hr raised ERS values from 2.20 to 4.80%. In a separate test slow cooling over 2 hr to 21 °C raised the ERS content from 3.65 to 6.35%. Multiple cook‐cool (3×) gave ERS contents of 23.2 and 18.2% for boiled potatoes held for 24 hr at 4 or 20 °C. Mashing and freezing raised ERS values by 1–2%.
Adsorption of β‐Lactoglobulin variants A and B to the air–water interface
Authors: Mackie Alan R. , Husband Fiona A. , Holt Carl , Wilde Peter J. 
Published: March 2003

Summary The adsorption of proteins to interfaces is a vital and complex process for the formation and stabilization of multiphase food systems (emulsions and foams). The process of protein adsorption is generally understood only at the phenomenological level, as the complexity of protein unfolding during adsorption is very difficult to predict and model. By comparing proteins with very similar structures, it is possible to attribute observed changes in adsorption behaviour. The A and B genetic variants of β‐lactoglobulin (β‐lg) differ by only two amino acids (Asp‐64, Val‐118 in A, and Gly‐64, Ala‐118 in B), thus making them ideal candidates for this type of comparison. In this study we monitored the surface behaviour of β‐lg A and B, measuring the surface tension and surface dilational modulus of adsorbed protein, and the compression behaviour of spread protein films. At pH 7, variant B lowered the surface tension and increased the surface dilational modulus more rapidly than variant A. Raising the pH to 7.8 should increase the level of dissociation into monomers. Indeed, this was confirmed by the rate of adsorption, which increased in both cases. Also, the surface tension of both variants was much lower than at pH7. Variant B was less sensitive to the change of pH than A. Regardless of pH, after 3 h adsorption the difference between the variants in surface tension or surface dilational modulus was negligible. The differences in surface behaviour between the variants are discussed in terms of interactions between monomers at and with the interface, and the dimer : monomer equilibrium in the bulk solution.
Glycation of bovine β‐Lactoglobulin: effect on the protein structure
Authors: Morgan François , Mollé Daniel , Henry Gwénaële , Vénien Annie , Léonil Joëlle , Peltre Gabriel , Levieux Didier , Maubois Jean‐Louis , Bouhallab Saïd 
Published: March 2003

Summary Since temperature and water activity are among the most important parameters that affect the Maillard reaction, the glycation sites in pure, native bovine β‐lactoglobulin were determined after a mild heat treatment (60 °C) in an aqueous solution and after a treatment under a restricted water environment (50 °C, 65% relative humidity). In both systems, the results obtained underlined the structural heterogeneity of β‐lactoglobulin (β‐LG) glycoforms with respect to the number of lactose residues linked per protein molecule and to the binding sites involved. Subsequently, the effect of the glycation conditions on both the association behaviour and the conformational changes of the glycated β‐LG were characterised by proteolytic susceptibility, binding of the fluorescent probe 8‐anilino‐1‐naphtalene‐sulfonic acid, SDS‐PAGE and size exclusion chromatography. The results showed that dry‐way glycation did not significantly alter the native‐like behaviour of the protein while the treatment in solution led to important structural changes. These changes resulted in a specific denatured β‐LG monomer, which covalently associated via the free thiol group. The homodimers thus formed and the expanded monomers underwent subsequent aggregation to form high molecular weight species, via non–covalent interactions. The use of monoclonal antibodies with defined epitopes, raised against native β‐LG, confirmed that the protein conformation was much more modified when glycation was performed in a solution while the structural changes induced during dry‐way treatment were limited to the AB loop region of the protein.
Aspects of whey protein usage in infant nutrition, a brief review
Authors: Jost Rolf , Maire Jean‐Claude , Maynard Françoise , Secretin Marie‐Christine 
Published: March 2003

Summary Demineralized whey, whey protein concentrates and, to a lesser extent, some other whey protein fractions are key raw materials in infant formula manufacture. An estimate of the amount of whey protein used in infant formulae annually is in the order of 30–40 000 tons. Infant formula development has been a long lasting effort to approach the nutrient composition of human breast milk while using cow's milk as the raw material. This required extensive fractionation of the bovine milk followed by subsequent recombination of specific fractions. Criteria to judge protein quality and define adequate protein quantity in infant formulae have also evolved. Early criteria for protein adequacy were based on Protein Efficiency Ratio (PER) testing in rats and/or nitrogen balance studies. More recently, the approach of essential amino acid scores, based on the amino acid pattern of mature human milk has been put forward. Regulatory authorities such as CODEX, EC Commission and more recently LSRO in its suggestions to FDA in the USA, have issued reference amino acid profiles which are based on the average amino acid composition of human milk. The same authorities have also regulated protein density in infant formulae, accounting for an observed protein mean density of 1.5–1.6 g /100 kcal in mature breast milk. The minimum protein level of cow's milk based infant formulae was fixed at 1.8 g/100 kcal by these authorities. Current infant formulae have however protein densities significantly higher than the minimum of 1.8 g/100 kcal. The higher protein density compensates for the likeliness that the protein in the best of the formulae, is not as ideal for the infant as the protein from breast milk. Even if a complete equivalence may be difficult to reach, efforts continue in the direction of further optimizing the protein quality in terms of essential and semi‐essential amino acid profiles. This is the only way to be able to lower the protein content in a formula to levels that are nearer to the low protein density of human milk. Among several possibilities, the increase in the mass proportion of bovine α‐lactalbumin is a particularly promising way to achieve this goal.
Effects of pressure‐shift freezing and conventional freezing on model food gels
Authors: Kalichevsky‐Dong Monica T. , Ablett Steve , Lillford Peter J. , Knorr Dietrich 
Published: March 2003

Summary Gels of agar, starch, ovalbumin, gelatin and an industrial β‐lactoglobulin protein isolate, were frozen conventionally in a −30 °C freezer and by pressure‐shift freezing at 200 MPa at −15 °C. Thawing was carried out conventionally at 20 °C and by the application of a pressure of 200 MPa. The microscopic structure and mechanical properties of the thawed gels were compared with those of the initial gels. Microscopic examination showed that pressure‐shift freezing produces smaller and more uniform ice crystal damage than conventional freezing at −30 °C. The results also suggest that the freeze‐thaw behaviour of food gels can be categorized into two general types: (1) gels which have a reduced gel strength as a result of mechanical damage to the gel microstructure caused by ice crystal formation, and (2) gels which have an enhanced gel strength, as a result of molecular structural changes that take place in the frozen state. Agar and gelatin were found to be typical of type (1) gels, whereas starch, β‐lactoglobulin protein isolate and ovalbumin were found to be typical of type (2) gels. In the case of starch, retrogradation during thawing was found to be the most important factor.
Measurement of glass transition in native wheat flour by dynamic mechanical thermal analysis (DMTA)
Authors: Pereira Pedro M. , Oliveira Jorge C. 
Published: March 2003

Summary This work describes a method to study glass transition on native starch powders, based on dynamical mechanical thermal analysis using compression tests, and was applied to wheat flour (13.5% water content). This method will allow the determination of Tg in native (unprocessed) starchy materials, with minimal disturbance of the natural structures. The influence of the test conditions (heating rate, frequency and strain) on the glass transition measurements was determined using factorial designs. The values of Tg determined as the maxima of the energy dissipation (peaks in E″) of native flour and of freeze‐dried pre‐gelatinized flour were not statistically different (around 64 °C). The heating rate did not affect the measurements in the range tested (0.25 to 1 °C min−1). An interactive effect of the strain amplitude and the frequency was detected. The significance of this interaction can be caused by differences in mechanical energy dissipation, which would indicate that not only temperature but also the total energy input may affect this transition. Slight effects of phase separation between gluten and starch were found on native flour.
The fate of cyanogens during the cooking of cassava in mumu, a traditional oven in Papua New Guinea
Authors: Sopade Peter A. 
Published: March 2003

Summary Four (Alotau, Mt. Hagen, Goroka, and Rabaul) types of mumu (earth‐oven) in Papua New Guinea were evaluated to ascertain their potential to detoxify cassava. The acid hydrolysis method was used for the determination of cyanogens. Each mumu exhibited different detoxification capacity. The loss of cyanogens in the (coconut) creamed cassava dough was lower than in the uncreamed dough. This was more evident when coconut cream–cassava mixture was cooked in boiling water than in a conventional oven set at 180 °C. Certain interactions were suspected to exist between the coconut cream and cyanogens or between the coconut cream and the appropriate enzymes that are responsible for the hydrolysis of the cyanogens. Such interactions resisted the loss of cyanogens and/or their quantification by the analytical method. The results are discussed in the light of nutritional consequences of such interactions, as coconut cream is a popular dietary item in Papua New Guinea (and the South Pacific islands).
Effects of peeling methods on the quality of ready‐to‐use carrot slices
Authors: Barry‐Ryan Catherine , O’Beirne David 
Published: March 2003

SummaryThe effects of methods used for peeling and physiological age (over‐wintering) on the quality and storage life of carrot disks packaged in modified atmosphere were examined. Commercial mechanical abrasion peeling using fine or coarse carborundum plates, was compared with carrots peeled by hand, before slicing into disks. Slices which had been peeled by abrasion had higher respiration rates, greater microbial contamination and growth rates, higher pH values, higher rates of weight loss and shorter microbiological shelf‐lives than those which had been hand peeled. These results reflected the higher quality of the manually peeled carrots. Micrographs of the peeled surfaces confirmed that abrasion peeling inflicted greater damage. Carrots lifted in the autumn produced slices with longer shelf‐lives than carrots lifted in the spring after over‐wintering in the ground for four months.
Impact of fermentation technology on the phenolic and volatile composition of German red wines
Authors: Fischer Ulrich , Strasser Mario , Gutzler Karlheinz 
Published: March 2003

SummaryHomogenous grape material of the red varieties c.v. Pinot noir, c.v. Dornfelder and c.v. Portugieser were fermented on an industrial scale using a special fermenter for pump over and punch down treatment. On pilot scale, thermovinfication was carried out at 60 °C and a manual punch down treatment was used in open containers. Both the mechanical punch down and pump over treatment significantly enhanced the extraction of all phenolic compounds and their polymerization in comparison to the traditional manual punch down treatment. Applying an excess of mechanical maceration increased the extraction of seed and stem phenols, but slowed down their polymerization. Assessing volatile composition, the biggest differences occurred between wines made by thermovinification versus those fermented on their skins. Slow fermentation kinetics and low solid content in the juice enhanced ester formation in thermovinied wines. Thermal inactivation of lipoxygenase enzyme systems reduced C6‐alcohols and their subsequent esters in thermovinified wines. Only small differences occurred between punch down and pump over tanks except that the pump over regime gave all varieties of wines significantly higher quercetin levels. In conclusion, the application of modern fermentation equipment seemed to be more relevant to improve extraction and polymerization of phenolic compounds, while thermovinification yielded wines with high ester content giving a more fruity style.
Copper and iron determination in edible vegetable oils by graphite furnace atomic absorption spectrometry after extraction with diluted nitric acid
Authors: De Leonardis Antonella , Macciola Vincenzo , De Felice Martino 
Published: March 2003

SummaryIn this article, a new method for determining copper and iron in edible vegetable oils by using atomic absorption spectrometry is discussed. The metals were extracted from low quantities of oil (1–2 g) with a 10% nitric acid solution. The acid solution obtained can be injected directly into the atomic absorption furnace. The proposed method is simple and allows copper and iron to be determined in edible vegetable oils with a precision estimated below 15% relative standard deviation (RSD) for Cu and 10% for Fe.
Detection of adulteration of Basmati rice with non‐premium long‐grain rice
Authors: Bligh Heather F. J. 
Published: March 2003

SummaryBasmati rice is, on average, sold at 2–3 times the price of other rice available on the world market. As such, there is a requirement for a method that would allow the detection of non‐Basmati long‐grain rice within samples of Basmati. This paper reports the use of fluorescent simple sequence length polymorphisms (SSLPs) between known Basmati rice cultivars and likely adulterants, to detect the presence of any adulterant. The competitive nature of the fluorescent detection method also enabled crude estimations of the amount of adulteration present in blind test samples. Further, the difficulty in quantifying the level of adulteration is discussed.
Low temperature blanching effect on the changes in mechanical properties during subsequent cooking of three potato cultivars
Authors: Verlinden Bert E. , Yuksel Dogan , Baheri Mohammad , De Baerdemaeker Josse , Van Dijk Cees 
Published: March 2003

SummaryEight mechanical properties of three potato cultivars were measured during low‐temperature blanching (55, 65 and 75 °C) and subsequent cooling and cooking treatments. The mechanical properties were determined with a ring tensile test. Force‐based properties showed a decrease in value during blanching and cooking, whereas deformation‐based properties showed an initial increase during blanching, before decreasing, during cooking or after longer blanching times. This behaviour was attributed to the loss of turgor of the fresh potato tissue. Rates of change of mechanical properties during cooking depended on the pre‐blanching treatments: longer blanching times resulted in a slower decrease of the mechanical properties. The overall behaviour during blanching and cooking of the three cultivars was similar. A principal component analysis on the measured mechanical properties, for each blanching temperature separately, was used to study the blanching temperature effect and to segregate potato cultivars on their cooking behaviour.