UPGRADING SPENT LAYER MEAT BY MECHANICAL DEBONING AND FURTHER PROCESSING

Spent layer chickens, an underutilized, inexpensive source of animal protein in the United States, were used to produce an acceptable all chicken frank following mechanical deboning of the chicken parts without pregrinding. The franks were subjected to shear tests and compared to two well-known commercial brands of chicken franks for overall acceptability by an untrained 59 member panel. The franks produced from mechanically deboned spent layer chickens (Lab franks) had greater resistance to shear than the two commercial brands and the panelists showed significantly greater preference for one of the commercial brands. Comments of the panelists indicated the texture of the lab-prepared franks was tougher than the two commercial brands. However, 12 members of the panel stated the lab-frank texture was tender. Collagen content of the spent layer franks was no higher than for the commercial brands. It is therefore concluded that the toughness could have been due to the nature of the myofibrillar proteins. Such toughness could be modified by tenderizing enzyme treatment of the raw material to produce varying degrees of frank softness or firmness depending on consumer preference.     

STRESS RELAXATION AND TENSILE STRENGTH TESTING OF A PROCESSED FISH PRODUCT

Minced silvercarp was prepared as cooked loaves containing only various added salts. The loaves were then subjected to stress-relaxation and tensile strength tests. The various treatments gave different compression forces, relaxation T_50% values and tensile strengths. The compression force measurements were closely correlated with tensile strength values. Both compression force and tensile strength might be related to the binding quality (cohesiveness) of the loaves. The relaxation T_50% values were not closely correlated with the compression forces nor the tensile strengths, and might be related to the product's viscoelastic properties. Different percent deformation did not have a significant effect on the relative order of the compression force values, but did affect the relaxation T_50% values, with larger differences between samples at 25% deformation.     

Glass Formation and Properties in the System Calcia-Gallia-Germania

The critical cooling rate for glass formation, R^c, was measured for four compositions in the system calcia-gallia-germania. The activation energy, E, and frequency factor, u, for the crystallization process were determined by reheating the glasses at varied constant heating rates and measuring the temperature of crystallization. Both E and v increased, with increasing germania content of the glass, whereas R^c decreased. The density, refractive index, and Abbe number were also measured; all decreased with increasing GeO² content. These results are compared with those for calcia-gallia-silica glasses of comparable compositions.     

APPLICATION OF CORRELATION BETWEEN BIOT AND DINCER NUMBERS FOR DETERMINING MOISTURE TRANSFER PARAMETERS DURING THE AIR DRYING OF COROBA SLICES

The moisture mass transfer parameters characterizing the air drying of coroba slices were determined using the correlation between Biot and Dincet numbers. The air drying was carried out at temperatures of 71, 82 and 93C and velocities of 0.82, 1.00 and 1.18 m/s. Experimental moisture content data for coroba slices were collected. The drying coefficient and lag factor were calculated from the experimental data and were incorporated into the correlation. The moisture diffusion coefficient, Biot number and mass transfer coefficient ranged between 1.147  ×  10 ^{− 12} –3.740  ×  10 ^{− 12}  m²/s, 0.097–0.114 and 0.903  ×  10 ^{− 4} –1.729  ×  10 ^{− 4}  m/s, respectively. The predicted dimensionless moisture content profiles showed adequate agreement with the experimental observations, with the mean relative error between 0.98 and 4.61%.

PRACTICAL APPLICATION

As drying is an energy-intensive operation, it has become the prime concern of the researchers to optimize process conditions that lead to energy savings. Moisture transfer parameters are important transport properties needed for accurate modeling in food drying applications. Therefore, accurate determination of these parameters for the drying operation is essential. There is a large amount of studies available in the literature to determine and calculate these parameters for the products subjected to drying. But limited studies have been carried out to determine these parameters using the drying process parameters in terms of lag factor and drying coefficient as first introduced by Dincer and Dost.     

USE OF MALIC ACID AND OTHER QUALITY STABILIZING COMPOUNDS TO ASSURE THE SAFETY OF FRESH-CUT "FUJI" APPLES BY INACTIVATION OF LISTERIA MONOCYTOGENES, SALMONELLA ENTERITIDIS AND ESCHERICHIA COLI O157:H7

The effectiveness of malic acid in combination with physicochemical quality stabilizing compounds to inactivate Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7 inoculated in fresh-cut "Fuji" apples packaged in air and stored at 5C was evaluated. Apple pieces were immersed for 1 min in solutions containing 1% w/v N-acetyl-L-cysteine, 1% w/v glutathione and 1% w/v calcium lactate with and without 2.5% w/v D-L malic acid to control apple browning, softening and reduce the populations of pathogenic microorganisms. Fresh-cut apples dipped in each solution were then inoculated with L. monocytogenes, S. Enteritidis or E. coli O157:H7 . The use of malic acid in combination with physicochemical quality stabilizing compounds caused more than 5 log₁₀ cfu/g of L. monocytogenes, S. Enteritidis and E. coli O157:H7 counts. The results obtained in this work pointed out the potential use of malic acid in combination with physicochemical quality stabilizing compounds as a good alternative for safety assurance of fresh-cut apples.

PRACTICAL APPLICATIONS

The use of organic acids such as malic acid, as well as physicochemical quality stabilizing compounds such as N-acetyl-L-cysteine, glutathione and calcium lactate on fresh-cut fruits can benefit the fresh-cut products industry, since they can assure the safety and quality of these products. The main reason for their suitability is their natural origin, thus resulting in fruits that are both attractive and healthy for the consumers who demand fresh-like products.     

Quality changes in the fresh water prawn, Macrobrachium rosenbergii during storage on ice

The effect of stratification in ice on the quality of fresh water prawns was monitored by microbiological, subjective and objective textural analyses. In general, prawns in the lower layers of ice exhibited more marked textural changes and greater numbers of potential spoilage bacteria were found on them. No connection was found between the number of proteolytic bacteria and textural changes in the prawn muscle.     

SALT CONTENT OF KOSHER CHICKEN PARTS STUDIED UNDER CONTROLLED CONDITIONS

Salt content in the breast, thigh and skin was determined in chickens which had been kosher-processed with different salting times, quantities and different numbers of rinses and after cooking. Significant differences in the salt content were obtained after 1.5 h of salting. Salt quantity significantly affected only the thigh and skin. Rinsings had no effect in reducing salt content in the breast and thigh. Cooking did not reduce the salt content of the chicken except in the skin. The salt treatments used in this study, which were similar to those used in commercial kosher dressing plants, did not increase uptake of water.