H. W. Ockerman

Lipid oxidation and color change of salted pork patties.

The purposes of this study were to explore the interaction of lipid oxidation and pigment oxidation in salted pork patties and to study the mutual relationship between lipid and pigment oxidation caused by replacing sodium chloride with potassium chloride at low salt levels. For fresh pork patties, a(∗) and b(∗) values decreased with the replacement of sodium chloride by potassium chloride. However, there were no significant differences of L(∗) values, pH values, total pigments and heme irons by replacement of NaCl with KCl; however, the replacement reduced 2-thiobarbituric acid reactive substances (TBARS). The addition of sodium tripolyphosphate, ascorbic acid and carnosine did not change a(∗) and b(∗) values of raw pork patties. However, raw pork patties with 0.25% sodium tripolyphosphate had significantly higher L(∗) value compared to other samples. The pH of raw pork patties with 0.5% carnosine was higher than those of other treatments. The pH of raw pork patties with 0.25% sodium tripolyphosphate was significantly higher than that of the control treatment with no antioxidant. Samples with 550ppm ascorbic acid had significantly higher total pigment and heme iron than patties with 0.25% sodium tripolyphosphate. Although control treatment with no antioxidant had slightly higher TBARS values, these differences were not large enough to be significant.

Inactivation and attachment of Listeria monocytogenes on beef muscle treated with lactic acid and selected bacteriocins

Cubical pieces (1 cm3) of aseptically obtained beef muscle were treated with lactic acid (2%), nisin (4 × 104 IU/ml) and pediocin PO2 (a bacteriocin produced by Pediococcus acidilactici PO2; 3.2 × 103 arbitrary units/ml). Treated meat was immersed for 1 min in a cell suspension of a mixture of two strains of Listeria monocytogenes and then stored for 48 h at 4°C. Meat cubes were analyzed immediately after immersion in the cell suspension, then after 1, 24, and 48 h of storage. Count of L. monocytogenes per cube and percentage of attached cells were determined. Data indicated that the antimicrobial agents significantly (p = 0.05) decreased the count of L. monocytogenes during the 48-h storage by 1.7, 1.1, and 0.6 log10 CFU/6 cm2 of meat surface for lactic acid, nisin, and pediocin PO2 treatments, respectively. Lactic acid on the meat surface had an immediate and also a delayed listericidal action, but bacteriocins only inhibited L. monocytogenes immediately, and had little or no delayed antilisterial effect. The percentage of Listeria cell attached to the beef muscle significantly (p = 0.05) increased in the presence of lactic acid, but the value did not change significantly or slightly decreased in the presence of nisin and pediocin PO2, respectively.

USE OF ACETIC AND LACTIC ACID TO CONTROL THE QUANTITY OF MICROORGANISMS ON LAMB CARCASSES1

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.

Diffusion of Curing Brine in Tumbled and Non-Tumbled Porcine Tissue

Tumbling action and time of tumbling both increased the migration of individual cure components of sodium chloride, dextrose, sodium nitrite as well as the average brine (average migration of these components) in porcine tissue. In most instances the difference became apparent after 3 or 4 h (tumbled 10 min/h) of treatment and remained significantly (P < .05) different during the remainder of the 18-h treatment period.

Effect of phosphate with tumbling on lipid oxidation of precooked roast beef.

This study was a 4×2×4 factorial experiment, sodium tripolyphosphate (0, 0.25, 0.4 and 0.5%), tumbling (nontumbled and tumbled), and storage time (day 0, 2, 4 and 7). Cooking yield was dependent on the level of phosphate and tumbling. For thiobarbituric acid reactive substances (TBARS) values, only sodium tripolyphosphate level and storage time had a significant two-way interaction. The TBARS value of tumbled roast beef with phosphates was the same as that of nontumbled roast beef. For the interaction of phosphate level and storage time, roast beef without phosphate had the significantly highest TBARS values compared with other phosphate levels at day 4 of storage. At day 7, the addition of 0.5% phosphate maintained the oxidative stability of precooked roast beef. The use of 0.5% sodium tripolyphosphate, an iron chelator, should be an effective strategy to reduce the formation of TBARS in precooked roast beef.

Sensitivity of three pathogenic bacteria to Turkish cemen paste and its ingredients.

Pastirma is a dry cured meat product which is pasted with cemen. This paste is prepared from ground fenugreek, garlic and red hot pepper (RHPP). In this study, the cemen mix/paste and all its ingredients were tested for their inhibitory effects on Escherichia coli, Staphylococcus aureus and Yersinia enterocolitica. All samples had a varying inhibitory effect against all the bacteria tested during 4 days of storage. Complete cemen paste showed the strongest inhibitory effect on the three pathogens compared to ingredients alone. Fenugreek and RHPP had a bacteriostatic effect while the cemen paste and garlic had a bactericidal effect. S. aureus was the most sensitive bacterium while Y. enterocolitica was the most resistant. The results of this study confirmed the protective effect of cemen paste and garlic in food preservation especially against E. coli, S. aureus and Y. enterocolitica proving safety for public health. Hence it might be concluded that cemen paste is the first hurdle to prevent bacterial contamination, and a low pH (∼4.83) value would also add an additional barrier to secure safety of the product. Finally, it can be suggested that similar studies should be conducted on actual meat systems to confirm these findings.

Thermal Destruction of Microorganisms in Meat by Microwave and Conventional Cooking

When heating ground beef to internal temperatures of 34, 61, and 75 C, high temperature (232 ± 6 C) oven cooking was more effective for bacterial destruction than low temperature (149 ± 6 C) oven cooking. Low temperature oven cooking was more effective than microwave cooking. These differences in microbial destruction rates became significant (P<05) when the meat reached the 75-C internal temperature level.

Model system evaluations of the effects of different levels of K2HPO4 NaCl and oil temperature on emulsion stability and viscosity of fresh and frozen turkish style meat emulsions

The effects of different levels of K(2)HPO(4), NaCl, and the effects of oil temperature used in the evaluation of emulsion stability and viscosity of fresh and frozen beef (fat level adjusted with tail fat from sheep) was studied by utilizing a model system. Emulsion stability (ES) and emulsion viscosity (EV) of frozen meat tissue were both decreased, by 3·6% and 10·5% respectively, when compared to fresh meat. ES was decreased by 4·0% and 3·7% at 5°C and 11°C oil temperature respectively when compared to 21°C. While EV decreased 12·2% at 11°C compared to 21°C, it did not show any statistically significant (P < 0·01) change at 5°C oil temperature. ES and EV were elevated with the addition of phosphate and increasing phosphate levels. These increases for ES were 3·9% and 3·7% with 0·50% and 0·75% phosphate levels respectively, when compared to the 0·00% phosphate control group. Also, the increases for EV were 22·3% and 27·0% with 0·50% and 0·75% phosphate levels respectively, compared to the 0·00% phosphate control group. The alteration of the ES was not statistically P < 0·01) significant for the 0·50% phosphate level when compared to the 0·75% phosphate level. The ES decreased 1·1% for a 3·0% salt level when compared to a 2·5% salt level, and there was statistically (P < 0·05) no effect on the EV.

Effects of anka rice, nitrite, and phosphate on warmed-over flavor and palatability characteristics in roast beef.

Effects of anka rice, nitrite, and phosphate used in surface curing of roast beef on chemical analysis, lipid oxidation, sensory evaluation, physical measurements, and microbial growth after refrigerated storage were studied. TBA values indicated that nitrite retarded lipid oxidation and inhibited development of warmed-over flavor; however, anka rice had a flavor masking effect on oxidation; and phosphate did not improve physical measurements due to surface curing but slightly inhibited oxidation. There was a synergistic effect among anka rice, nitrite, and phosphate in some measurements.

Saprophytic and Pathogenic Bacteria Levels in Turkish Soud-jouks Manufactured in Erzurum, Turkey1

In Turkey, spicy, typically dry, fermented sausage (soudjouk) is one of the most popular processed meat products. In this study, 42 soudjouk samples were collected from the eight manufacturers in Erzurum, Turkey. These samples were evaluated for aerobic plate count (APC) at 37 and 25°C, psychrotrophic, coliform, Escherichia coli , and coagulase-positive Staphylococcus aureus counts and presence of Salmonella and Shigella spp. Generally, all the samples had very high counts of most of the bacteria enumerated. In two samples of the 42, Shigella spp. was found and one of them was Shigella boydii . None of the samples yielded Salmonella spp.