1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

RUNNING HEAD- SURFACE FLAMING REDUCES BACTERIA IN BEEF TRIM 

Bacterial Populations Response to Surface Flaming 

In Beef Trim Destined for Retail Markets 

Thomas R. Vosen1, William B. Mikel3*, Susan Dale1, 

Donald E. Conner2, William R. Jones1, and 3Melissa Newman 

1

Department of Animal and Dairy Sciences, Auburn University, Auburn

University, AL 36849 

2

Department of Poultry Science, Auburn University, Auburn 

University, AL 36849 

3

Department of Animal Sciences, University of Kentucky, Lexington,

KY 40546 

*

Address all inquiries to author Mikel at Room 205, Animal Science

Building, University of Kentucky, Lexington, KY 40546. (859)

257-7550. Fax (859) 257-5318 
3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

1 Running Head - Meat microbiology, Ground beef, Fat, Flame

2 

Beef Trim and Surface Flaming 

ABSTRACT 

Frozen, vacuum packaged semitendinosus muscles, from "cull" 

cows were used as beef trim. Meat was tempered at 0oC for 48 h with 

half of the muscles trimmed of all visible fat while the remainder 

were allowed to retain all external fat. Muscles were sliced into 

1.27 cm2 wide strips, with the length of the strips determined by 

the width of the muscle and then tempered at 4.4oC for an 

additional 12 h. This experiment utilized four treatments, a low 

and high fat control in which flame was not applied and low and 

high fat treatments in which 10 seconds of surface flaming was 

utilized. After treatment, beef trim was ground, formed into 

patties, and placed in cooler storage for 0, 1, 2, 4, or 8 days. 

Treatment HF0 patties (high fat, no flame) had higher (P<0.01) 

aerobic-plate-counts (APC) than all other patties. High fat 

products were shown to display higher (P<0.01) APC than lower fat 

patties. LF0 (low fat, no flame) patties and LF10 (low fat, 10 

seconds flame) had similar (P>0.05) psychrotrophic-plate-counts 

(PPC), however, were lower (P<0.01) than both HF0 and HF10 (high 

fat, 10 seconds flame) patties. Moreover, HF10 patties had less 

(P<0.01) PPC than did HF0 patties. Also, lower fat products 

showed fewer (P<0.01) PPC than higher fat products. Evaluation of 

pseudomonas counts (PSU) showed HF0 patties to possess more 

(P<0.01) organisms than all other products. Additionally, F10 and 

LF0, and LF10 and HF10 had similar (P>0.05) values. 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

Beef Trim and Surface Flaming

 INTRODUCTION 

The production of ground beef in this country is vital to the 

processing industry, since 44% of the fresh beef consumed in this 

country is in this form (2). Research must be conducted that will 

allow processors to utilize resources that currently exist within 

their facilities to reduce microbial populations of beef trim 

without physically degrading the product. 

Whether it be a high or low fat product, maximizing the 

shelf-life of red meat can be accomplished by controlling 

microbial contamination and further growth during fabrication of 

primal, subprimal, and retail cuts (1). However, differences do 

occur in microbial populations which are dependent upon fat type. 

(10, 18) reported that microbial populations for certain 

organisms were higher on fat tissue than on lean tissue. They 

postulated that this difference was pH linked. With countless 

articles devoted to the storage of meat products, very few deal 

with the direct application of heat to the lean surface for the 

explicit purpose of reducing microbial populations. Most of the 

past research in this area has been aimed at the reduction of 

microorganisms obtained from fully cooking a product. Surface 

sterilization by surface heating would surely require an 

inordinate length of contact between the heat source and the meat 

surface, but for microbial population reductions, contact between 

the heat source and lean meat surface can be minimized. 

The objective of this experiment was to determine the effect 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

Beef Trim and Surface Flaming 

of surface flaming on low and high fat beef trim in reference to 

possible microbial population reductions in both and the possible 

differing effect surface flaming might impart upon either. 

Materials and Methods 

Processing Procedure: 

Whole semitendinosus muscles from carcasses of "cull" cows 

were obtained from Lambert Meats Laboratory (Auburn University, 

AL) and vacuum sealed before freezing at -20oC for one month. Upon 

experimental initiation, meat was tempered at 0oC for 48 h with 

half trimmed of all visible fat and the remainder retaining all 

external fat. Muscles were sliced into 1.27 cm2 strips, with the 

length of the strips determined by the width of the whole muscle. 

Low fat (1.60% fat) and high fat (20.25% fat) (3) beef strips 

were placed in covered pans and tempered at 4.4oC for an additional 

12 h. Lean beef strips were then divided into four, 2.95 kg 

treatments. At this time all equipment contact surfaces were 

sterilized with a 70% ethyl alcohol solution. Beef strips were 

weighed and placed on a sterile stainless steel mesh belt which 

allowed for simultaneous treatment of beef strips at a distance of 

6.35 cm (between the meat and heat source) both dorsally and 

ventrally. Flame was used as a heat source in this experiment, 

with meat and flame contact lengths of 0 and 10 seconds used. 

Treatments used were: LF0 = low fat, no heat, HF0 = high fat, no 

heat, LF10 = low fat, flame 10 seconds, HF10 = high fat, flame 10 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

seconds. After treatment, beef strips 

Beef Trim and Surface Flaming 

were weighed, ground twice through a 4.5 mm grinding plate using a 

Mixer/Grinder (Kitchen Aid Model #KSM90WH, St. Joseph, MO), formed 

with a conventional hand pattie press into 113.5 g patties, placed 

onto styrofoam meat trays and covered with an oxygen permeable 

film. Patties from each treatment were stored for one of five 

periods ( 0, 1, 2, 4, and 8 days) of cooler storage at 1.7oC. 

Microbial Analysis: 

Populations of aerobic, lactic acid bacteria, and 

psychrotrophic bacteria were enumerated during each storage 

period. At each sampling period, meat patties were removed from 

storage and two 11 g samples were aseptically removed from pattie 

centers and placed into sterile plastic bags (Fisher Whirl Pak, 

530 ml, Pittsburgh, PA) with 99 ml of Butterfield's phosphate 

buffered diluent (35 g KH2PO4 in 500 ml of distilled water adjusted 

to pH 7.2 with 1 N NaOH and brought to 1 liter with distilled 

water). Each sample was homogenized using a Model 400 Stomacher 

(Tekmar Company, Cincinnati, OH) for two minutes. Samples were 

serially diluted and plated using a Spiral Plater Model D (Spiral 

Systems Instruments, Bethesda, MD). Aerobic-plate-counts (APC) 

were enumerated on standard methods agar (SMA) (BBL Microbiology 

Systems, Cockeysville, MD) with plates incubated at 40o

C for 48 h. 

Psychrotrophic-plate-counts (PPC) were determined on standard 

methods agar (SMA) (BBL Microbiology Systems, Cockeysville, MD) 

with plates incubated at 4.4oC for 7 days. Pseudomonad counts 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

(PSU) were enumerated on heart infusion agar (Difco, Detroit, MI) 

with 1% Beef Trim and Surface Flaming 

ceporin, 1% fucidin and 1% cetrimide added (CFC agar), with plates 

incubated at 30oC for 48 h. Lactobacillus-plate-counts (LPC) were 

determined on MRSA broth with 2% added agar (Difco, Detroit, MI) 

with plates incubated at 40oC for 48 h. After appropriate 

incubation, plates were counted with a Bacteria Colony Counter 

Model 500A (Spiral Systems Instruments, Bethesda, MD). All 

microbial data were expressed in log10 cfu's/g of sample. 

Metmyoglobin: 

Determination of metmyoglobin concentration (4) was performed 

in duplicate at each storage period. Samples (5 g) were added to 

50 ml of 0.04 M phosphate buffer (pH 6.8) and homogenized for 30 

seconds with a Pro250 Homogenizer (Monroe, CT). The homogenate 

was then centrifuged for 30 minutes at 5oC (50,000 x g) with the 

supernatant filtered through Whatman No. 1 filter paper and 

analyzed spectrophotometrically at 525, 572, and 730 nm using a 

Perkin-Elmer model #C688-0000 Lambda 4 UV/VIS spectrophotometer 

(Norwalk, CT). Measurement of metmyoglobin was calculated using 

the following formula (13) which utilized a turbidity correction 

(9). 

Met %=(1.395-((572A

-(730A*1.45))/(525A-(730A*1.73))))*100 

pH Determination: 

Determination of product pH was performed in duplicate at 

each storage period using 100 ml of deionized distilled H2O and 10 

g of product. The water and meat were mixed for 30 seconds using 

a Pro250 Homogenizer (Monroe, CT). Extech Instruments Corporation 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

Beef Trim and Surface Flaming 

model #120505 pH Meter (Waltham, MA) was used to determinate final 

product pH. 

Hunter Color Analysis: 

Objective product color measurements were obtained in 

triplicate for patties at each storage period using Hunter Labs 

D25 DP9000 (Reston, VA) Color Difference Meter. The unit was 

standardized using a white C2-36852 standard plate. Expression of 

values obtained were in Hunter Color "L", "a" and "b" units (11). 

TBARS Analysis: 

Analysis of 2-thiobarbituric acid reactive substances (TBARS) 

was determined in duplicate (12). 

Product Temperature: 

Post-treatment temperatures were obtained from freshly ground 

treatments at five randomly selected sites using Koch Supplies 

Incorporated AT-500 Digital Thermometer (Kansas City, MO). 

Compositional Analysis: 

Moisture, fat and protein analysis were performed in 

triplicate (3) on randomly selected samples taken from lean beef 

strips immediately prior to treatment. 

Visual Evaluation: 

Pattie surface discoloration was monitored at each storage 

period by a four member experienced panel. Each panelist viewed 

patties in a retail display case, which also approximated retail 

lighting conditions. The panelists were asked to determine 

percent pattie surface discoloration while viewing three patties 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

from each 

Beef Trim and Surface Flaming 

treatment. In addition, panelists were asked to evaluate percent 

surface fat smearing on three patties from each treatment 

immediately after processing was complete. 

Statistical Analysis: 

This experiment was arranged as a 2X2 factorial in a split 

plot over time with two fat levels, 1.5% and 22.5%, two time 

periods of surface heating (0 and 10 seconds), and five periods of 

cooler storage (0, 1, 2, 4, and 8 days) (16). This experiment 

utilized two replications with data being analyzed by general 

linear model (GLM). When differences were detected, means were 

separated by Student-Newman-Kuels (SNK) (15). 

Results and Discussion 

Microbiological Stability 

Fat surfaces comprise a significant part of red meat 

carcasses. For example, most of the surface of a freshly dressed 

carcass consists of subcutaneous fat. Hence, this tissue is most 

likely one of the first to become contaminated during the 

slaughter process (18). This would allow for greater microbial 

contamination of fat surfaces than for lean surfaces in processed 

products such as ground beef, which is usually manufactured using 

lean beef trim and a very high fat and potentially more 

contaminated fat/lean beef trim. The effectiveness of flame on 

high fat beef trim was shown as HF10 patties had lower (P<0.01) 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

APC than HF0, but was similar (P>0.05) to both low fat products 

(Table 1). As expected, APC 

Beef Trim and Surface Flaming 

increased as cooler storage lengthened (Table 3) with Day 0, 1, 

and 2 having similar (P>0.05), but lower values (P<0.01) than Day 

4 or 8. Day 4 patties had lower (P<0.01) aerobic populations than 

Day 8. APC over fat level (Table 4) showed higher fat products to 

be more contaminated (P<0.01) than lower fat patties. These 

findings are important, in that, although more highly 

contaminated, the use of surface flaming of 20.25% fat beef trim 

can lower microbial populations to that of very low fat beef trim. 

Since ground beef is a perishable product and in most retail 

instances is stored at temperatures conducive to psychrotrophic 

proliferation, these organisms become very significant in regards 

to product stability. As with APC, the use of flame in a high fat 

product (HF10) showed lower (P<0.01) PPC than HF0 patties (Table 

1). However, HF10 exhibited populations higher (P<0.01) than low 

fat products, which were similar (P>0.05). Psychrotrophic 

populations over time (Table 3) showed increases (P<0.01) at every 

day of storage. PPC values among fat types (Table 4) showed 

higher fat products to have higher (P<0.01) populations than 

products with less fat. Even though containing higher initial 

populations, the use of flame on high fat products could not lower 

PPC to that of low fat products. 

Pseudomonas has been found to be one of the most important 

spoilage organisms in reference to red meats (14). Pseudomonas 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

can be a particular problem in reference to ground beef, in that, 

it can grow at moderate temperatures, but is classified a 

psychrotroph Beef Trim and Surface Flaming 

(8, 6). As with other forms of microbial enumeration mentioned 

previously, HF10 had lower (P<0.01) PSU when compared to HF0 and 

was similar (P>0.05) to LF10 (Table 1). LF0 had lower (P<0.01) 

PSU than the higher fat products but was similar (P>0.05) to LF10. 

Over storage time, PSU counts were similar (P>0.05) for Days 0 

and 1, but lower (P<0.01) than Days 2, 4 and 8 which increased 

(P<0.01) chronologically (Table 3). Among fat types (Table 4), 

higher fat products displayed greater (P<0.01) PSU counts. 

Findings for PSU combined with those for PPC suggest that use of 

flame on high fat beef trim might not decrease populations of 

psychrotrophs as effectively as for overall aerobic populations. 

As previously stated, ground beef for retail consumption is 

usually displayed in an aerobic condition. However, even though 

presented in this state, proliferation of organisms which are 

basically anaerobic in nature can occur. One such facultative 

anaerobe is lactobacillus. Lactobacillus (LPC) showed no effects 

(P<0.05) over fat types (Table 4). This finding is of particular 

interest since higher fat patties were shown to display higher 

microbial populations than low fat patties. This was probably due 

to low LPC displayed by both high and low fat products. A 

significant (P<0.01) interaction was detected in reference to 

analysis of storage time * treatment for LPC (Figure 1). In 

general, values for LPC tended to be higher as storage time 

increased. Additionally, HF10 patties tended to have lower LPC 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

when compared to all other patties, while HF0 patties displayed 

the Beef Trim and Surface Flaming 

highest LPC at Day 8. 

In general, high fat patties were shown to contain higher 

microbial levels than low fat patties. The effect of surface 

flaming of high fat beef trim on pattie microbial populations 

seems very positive and in some cases produces microbial 

populations equivalent to those noted in the lower fat patties. 

TBARS Values 

Determination of lipid oxidation using the 2-thiobarbituric 

acid reactive substances test (TBARS), showed no differences 

(P>0.05) among treatment patties (Table 1) or fat types (Table 4). 

Among storage times (Table 3), TBARS values were different 

(P<0.01). Days 0 and 8 had similar (P>0.05) TBARS values, with 

Day 8 having higher (P<0.01) values than any other day. However, 

Day 0 while similar (P>0.05) to Days 1 and 2, displayed higher 

(P<0.01) TBARS values than those of Day 4. This effect of 

fluctuating oxidation values over time is probably due to 

breakdown of malonaldehyde to subunits which are not detectable by 

TBARS analysis (5). Also, a reduction in TBARS values may result 

if breakdown of malonaldehyde is greater than formation (19). 

pH 

Product pH affects microbial growth and product longevity. 

The closer the pH is to 7.0, usually the greater the population of 

microorganisms found. (18) found red meat carcasses to have fat 

tissue pH's about 1.0 pH higher than lean tissue. This higher pH 

value for fat tissue has been shown (18, 10) to result in 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

increased Beef Trim and Surface Flaming 

microbial growth when compared to lower pH lean tissue samples. 

LF10 had greater (P<0.01) pH values than HF10 and HF0, and HF0 

displayed a higher pH than (P<0.01) HF10 patties (Table 1). A 

general trend was revealed when analyzing by treatment. LF0 and 

HF0 products when compared to their low or high fat flamed 

counterparts had different product pH's (Table 4). This could be 

due to the fact that when initially heated, lipases and 

phospholipases, produce free fatty acids, thus, lowering product 

pH (7). Product pH over storage (Table 3) showed pH on Days 0 and 

1 to be similar (P>0.05), but higher (P<0.01) than Days 2, 4 and 8 

which were all similar (P>0.05). Lower fat patties possessed a 

higher (P<0.01) final product pH than the higher fat products. 

The findings for pH reported here are confusing, in that, as beef 

trim fat level increased, a similar increase should have been 

noted for ground beef pattie pH. 

Color Stability 

Metmyoglobin content of beef products, particularly retail 

ground beef patties is extremely important, since consumer 

purchasing choices of red meats are based to a high degree upon 

product color (17). Analysis for metmyoglobin content was 

conducted to determine pigment conversion in the final product. 

Significant (P<0.01) interactions occurred for storage time * 

treatment (Figure 2) and storage time * fat type (Figure 3). 

These two interactions are very much related, in that both reveal 

slight increases as storage time lengthened. However, between 

Days 4 and 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

Beef Trim and Surface Flaming 

8 of storage the higher fat patties showed marked increases in 

metmyoglobin content. 

Visual evaluation of product surface discoloration revealed 

significant (P<0.01) interactions for analysis of storage time * 

treatment (Figure 4) and storage time * fat type (Figure 5). In 

general, values for patties increased over time, however, as with 

the significant interaction of storage time * treatment in the 

analysis of metmyoglobin, HF0 patties displayed a marked increase 

in product discoloration between Days 4 and 8 of storage. Also, 

noted was that HF10 showed the lowest surface discoloration scores 

at Day 8. On the whole, increases were noticed for low and high 

fat patties over storage, with high fat patties initially 

displaying higher values. However, between Days 0 and 1 of 

storage, low fat patties showed greater increases in discoloration 

and over the remainder of storage magnitudes of differences 

between low and high fat products were extremely variable. 

Hunter color "L" values (lightness) were different (P<0.01) 

among treatment patties (Table 2) with high fat patties displaying 

similar (P>0.05), but higher (P<0.01), "L" values than either low 

fat product. LF10 displayed a lighter (P<0.01) colored pattie 

than LF0. No differences (P>0.05) were revealed for product "L" 

values over 0, 1, 2, and 4 days of storage (Table 3), however, 

each had higher (P<0.01) "L" values than Day 8. Product "L" 

values among fat types (Table 5) indicated higher fat patties had 

much lighter (P<0.01) colored patties than low fat products which 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

was entirely 

Beef Trim and Surface Flaming 

due to fat content. 

The use of Hunter "L", "a" and "b" values for evaluation of 

ground beef products is important, however, the Hunter "a" value, 

as it relates to ground beef, is the most effective of these. 

Hunter "a" values are an objective tool to evaluate meat redness 

properties. Hunter "a" values showed no differences (P>0.05) over 

fat types (Table 5). A significant (P<0.01) interaction was 

detected for Hunter "a" values for storage time * treatment 

(Figure 6). This interaction is probably closely related to those 

previously mentioned, in that over the first four days of cooler 

storage HF0 patties exhibited values superior to other treatment 

patties. However, between Days 4 and 8 the rate of degradation 

was much more rapid than that of other treatment patties. While 

tending to lower scores for product surface discoloration, HF10 

patties showed trends of lowering "a" values when compared to 

other lower fat products. 

Hunter "b" values (yellowness) were significant (P<0.01) 

among treatment patties (Table 2). Yellowness values were higher 

(P<0.01) for HF0 patties than for all other patties. HF10 patties 

displayed higher (P<0.01) values than either low fat product. 

Over storage (Table 3) the highest (P<0.01) "b" values were 

displayed on Days 1 and 2 while values on Days 4 and 8 were 

similar (P>0.05). Day 0 had lower (P<0.01) "b" values than Day 4. 

Due to fat content (Table 5), the higher fat products displayed 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

greater (P<0.01) "b" values than those of low fat products. 

Beef Trim and Surface Flaming 

While many interactions existed in reference to color 

stability, findings indicated that fat level probably played a 

more important role for color effects than the use of surface 

flaming. This was shown by the lack of extreme effects for LF10 

coupled with HF10 not showing the highest discoloration scores. 

Fat Smearing 

Surface fat smearing revealed differences (P<0.05) among 

treatment patties (Table 2). As expected, HF10 patties had 

greater (P<0.05) amounts of surface fat smearing than all other 

patties, which were similar (P>0.05). Among fat types, (Table 5) 

high fat patties displayed higher (P<0.01) smearing values than 

low fat patties. 

Post-Treatment Temperature 

Post-treatment temperature means were different (P<0.01) 

among treatments (Table 2). Post-treatments temperatures of LF0 

and HF0 while similar (P>0.05) were lower (P<0.01) than for the 

flamed treatments, which were also similar (P>0.05). No 

differences (P>0.05) were noted for post-treatment temperature in 

relation to fat type (Table 5). 

CONCLUSIONS 

Higher fat products contained greater microbial growth than 

their lower fat counterparts. However, the use of surface flaming 

on high fat beef trim showed very positive effects for microbial 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

growth and directly conflicts with the notion that increased 

Beef Trim and Surface Flaming 

microbial growth on fatty tissue is linked to high pH. Moreover, 

no effects of lipid oxidation was noted, even when surface flaming 

was used. The use of flame on high fat beef trim tended to lower 

surface discoloration scores at 8 days of storage and high fat 

patties had similar Hunter "a" values to those of the lower fat 

products. The use of surface flaming on high fat beef trim 

destined for ground beef production needs to be investigated more 

fully. Use of this system on even higher fat beef trim (50%) 

would be of great use to the beef processing industry and 

ultimately have applications to the "fast food" industry. 
1 

2 
Table 1. Effects of heat treatment on microbial, chemical and

physical characteristics of low and high fat beef trim. 

APCb PPCc PSUd TBARSe pH

TRTa log10 log10 log10

 cfu/g cfu/g cfu/g mg/kg

LF0 2.51g 2.75h 2.28h 0.88f 5.72f

 LF10 2.52g 2.69

h 2.41gh 0.95f 5.67g

 HF0 3.23f 3.48f 2.91f 0.90f 5.60

h

 HF10 2.70g 3.18g 2.59g 0.98f 5.56i SEMj 0.08 0.06 0.08 0.04 0.01 

aLF0=low fat, no surface heating, LF10=low fat, 10 seconds of

surface flaming, HF0=high fat, no surface heating, HF10=highfat, 10 seconds of surface flaming. baerobic-plate-counts. cpsychrotrophic-plate-counts. dpseudomonad counts. e2-thiobarbituric acid reactive substances. f-iMeans within columns 

with common letters are not different (P>0.05). jSEM=standard error of the mean. 
Table 2. Effects of heat treatment on color and physical

characteristics of low and high fat beef trim. 

TRTa Lb bc TEMPd SMEARe 

Co VALUE VALUE % 

LF0 31.57h 8.98i 11.94g 0.50g 

LF10 32.57g 9.35

h 16.94f 0.33g

 HF0 37.12f 10.66f 10.28g 2.33g 

HF10 37.56f 10.23g 16.11f 6.17f

 SEMj 0.23 0.10 0.20 1.22 

aLF0=low fat, no surface heating, LF10=low fat, 10 seconds of

surface flaming, HF0=high fat, no surface heating, HF10=highfat, 10 seconds of surface flaming. b"L" (lightness) value. c"b" (yellowness) value. dpost-treatment temperature. epercent product surface smearing. f-iMeans within columns with 

common letters are not different (P>0.05). jSEM=standard error 

of the mean. 

Table 3. Effects of storage period on microbial, chemical, physical and colo
characteristics of low and high fat beef trim. 

DAYa

 APCb

 log10

 cfu/g 

PPCc

 log10 

cfu/g 

PSUd

 log10 

cfu/g 

TBARSe 

mg/kg 

pH 

Lf

 VALUE 

0 1.51j 1.52l 1.22k 0.99hi 5.68

h 35.26h 

 1 1.64j 1.80k 1.21k 0.83ij 5.67

h 34.69

h 

 2 1.86j 2.30j 1.61j 0.90ij 5.62i 34.75

h 

 4 3.02i 3.54i 3.15i 0.79j 5.61i 34.94h  8 5.66

h 5.97

h 5.55h 1.14

h 5.62i 33.90i 

 SEMm 0.09 0.06 0.09 0.05 0.01 0.25 

a0, 1, 2, 4 and 8 days. baerobic-plate-counts. cpsychrotrophic-plate-counts. dpseudomonad counts. e2-thiobarbituric acid reactive substances. f"L" (lightne

value. g"b" (yellowness) value. h-lMeans within columns with common letters ar

different (P>0.05). 

mSEM=standard error of the mean. 
Table 4. Effects of fat type on microbial, chemical and physical

characteristics of low and high fat beef trim. 

APCb PPCc PSUd LPCe TBARSf pH

FATa log10 log10 log10 log10

 TYPE cfu/g cfu/g cfu/g cfu/g mg/kg

LF 2.51h 2.72h 2.35h 1.77g 0.92g 5.70g

 HF 2.96g 3.33g 2.75g 1.82g 0.94g 5.58

h

 SEMi 0.07 0.05 0.06 0.06 0.03 0.01 

aLF=low fat, HF=high fat. baerobic-plate-counts. cpsychrotrophic

-

plate-counts. dpseudomonad counts. elactobacillus-plate-counts. f2-thiobarbituric acid reactive substances. g-hMeans within columns with common letters are not different (P>0.05). iSEM=standard error of the mean. 
Table 5. Effects of fat type on color and physical characteristics of

low and high fat beef trim. 

FATa Lb ac bd TEMPe SMEARf

 TYPE VALUE VALUE VALUE Co % 

LF 32.07h 15.43g 9.17h 14.44g 0.42h 

HF 37.34g 14.92g 10.44g 13.19g 4.25g 

SEMi 0.18 0.22 0.08 0.76 0.92 

aLF=low fat, HF=high fat. b"L" (lightness) value. c"a" (redness) value.d"b" (yellowness) value. epost-treatment temperature. fpercent product

surface smearing. g-hMeans within columns with common letters are not 

different (P>0.05). iSEM=standard error of the mean. 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

REFERENCES 

1. Acuff, G. R., Vanderzant, C., Savell, J. W., Jones, D. K., 

Griffin, D. B., and Elhers, J. G. 1987. Effects of 

acid decontamination of beef subprimal cuts on the 

microbiological and sensory characteristics of steaks. 

Meat Sci. 19:217-226. 

2. AMI. 1990. Meat Facts '90. Education and Member Services 

Department, American Meat Institute, Washington, D. C. 

3. AOAC. 1984. Official Methods of Analysis, 14th ed., 

Association of Official Analytical Chemists, 

Washington, DC. 

4. Chen, C. M. and Trout, G. R. 1991. Sensory, instrumental 

texture profile and cooking properties of restructured 

beef steaks made with various binders. J. Food Sci. 

56:1457-1460. 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

5. Chu, Y. H., Huffman, D. L., Egbert, W. R. and Trout, G. R. 

1988. Color and color stability of frozen restructured 

beef steaks: Effect of processing under gas atmospheres 

with differing oxygen concentration. J. Food Sci. 

53:705. 

6. Eddy, B. P. 1960. The use and meaning of the term 

"psychrotrophic". J. Appl. Bact. 23:189. 

7. Fennema, O. R. 1985. Characteristics of muscle tissue. 

Food Chemisty. 2nd ed. P. 725-790. Marcel Dekker Inc. 

New York, NY. 

8. Gill, C. O. and Newton, K. G. 1978. The ecology of 

bacterial spoilage of fresh meat at chill temperatures. 

Meat Sci. 2:207. 

9. Goldbloom, D. E. and Brown, W. D. 1966. Turbidity 

correction for absorption spectra of colored 

solutions. Biochem. Biophys. Acta. 112:584. 

10. Grau, F. H. 1983. Microbial growth on fat and lean 

surfaces of vacuum packaged chilled beef. J. Food Sci. 

48:326-328. 

11. Hunter, R. S. and Harold, R. W. 1987. The Measurement of

 Appearance, 2nd ed. John Wiley and Sons, New York, NY. 

12. Ke, P. J., Cervantes, E., and Robles-Martinez, C. 1984. 

Determination of thiobarbituric acid reactive 

substances (TBARS) in fish tissue by an improved 

distillation spectrophotometric method. J. Sci. Food 

Agric. 35:1248-1254. 
1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

13. Krzywicki, K. 1979. Assessment of relative content of 

myoglobin, oxymyoglobin, and metmyoglobin at the 

surface of beef. Meat Sci. 3:1. 

14. Nickerson, J. T. and Sinskey, A. J. 1972. Microbiology of 

Foods and Food Processing. p. 19-141. American 

Elsevier Publishing Company, New York. 

15. SAS. 1985. SAS User's Guide: Statistics, 5th ed. 

Statistical Analysis System Institute, Inc., Cary, NC. 

16. Steele, R. G. D. and Torrie, J, H, 1980. Principles and

 Procedures of Statistics, 2nd ed. McGraw-Hill Book Co., 

New York, NY. 

17. Stewart, G. F. and Amerine, M. A. 1982. Introduction to 

Food Science and Technology. 2nd ed. p. 104. 

Academic Press Inc., New York, NY. 

18. Vanderzant, C., Savell, J. W., Hanna, M. O. and Potluri, V. 

1986. A comparison of growth of individual meat 

bacteria on the lean and fatty tissues of beef, pork 

and lamb. J. Food Sci. 51:5-11. 

19. Vosen, T. R., Rogers, R. W., Halloran, J. D., Martin, J. M. 

and Armstrong, T. 1993. Effects of bran source and 

level on sensory, storage, compositional and nutritive 

properties of low fat beef sloppy-joes. J. Muscle Foods 

4:71.