J. Vanderstoep

Post-Mortem Glycolytic and Physical Changes in Turkey Breast Muscle

Abstract Concentration of some glycolytic intermediates, pH and time to maximum contraction were determined on post-mortem P. superficialis muscle from two ages of White Cannon tom turkeys. The birds were clearly identifiable as “fast-” or “slow-glycolyzing” on the basis of the percentage of initial ATP remaining at 60 minutes post-mortem. The “slow-glycolyzing” birds had a higher initial ATP concentration and muscle strips from these birds required a longer time to achieve maximum contraction.

Residual Pinkness in Cooked Turkey and Pork Muscle

Abstract Pectoralis muscles from 12 and 18 week old turkeys and two porcine muscles, namely Longissimus dorsi and Psoas major, were examined for their red color after cooking at internal temperatures of 65, 75, 85, and 95° refrigerated storage of up to four days. By analysis of variance, temperature, storage time, and their interaction were found to influence red color. Proper cooking, achieved when an end-point temperature of 85°C is reached, did not totally produce a redless meat color. A pink tinge was still detected regardless of the type of meat an disappeared over several days of storage. Polynomial equations specific to muscle type, as well as a more general model for red color prediction, are presented.

Removal of bovine serum albumin from cow's milk using chicken egg‐yolk antibodies immobilized on chitosan gel

Polyclonal chicken antibodies raised against bovine serum albumin (BSA) were immobilized on chitosan gel for the immunoaffinity isolation of BSA from cows milk. Antibodies (IgY) against BSA were isolated from egg‐yolk, purified and antibody reactivity to antigen was measured. IgY developed against BSA was reduced by 2‐mercaptoethylamine. The reactivities of reduced and whole IgY against BSA were not significantly different. The reduced IgY was covalently linked to chitosan gel through stable covalent thioether linkages using sulfo‐succinimidyl‐4‐(N‐maleimidomethyl)cyclohexane‐l‐carboxylate (sulfo‐SMCC) as a cross‐linker. The density of antibody IgY immobilized on chitosan gel was approximately 3–5 mg per ml of chitosan gel. The ligand‐binding capacity of immobilized IgY towards BSA was 0.35–0.44 mg BSA per ml of chitosan gel. A single pass of skimmed milk through the column allowed the removal of BSA from the milk sample. The milk sample was analyzed, before and after immunoaffinity separation, by SDS‐PA...

Effect of Heat Treatment and Organic Acids on Bioavailability of Endogenous Iron From Wheat Bran in Rats

Abstract The conversion of endogenous iron from wheat bran into hemoglobin was evaluated by a hemoglobin regeneration assay in weanling anemic rats. Iron repletion diets were formulated with both baked and unbaked wheat bran in the form of muffins and with FeSO 4 as the reference standard. Hemoglobin iron regeneration efficiency for FeSO 4 was 65.1 percent, whereas similar values for wheat bran in various experimental diets ranged from 46.1 to 66.5 percent. Baking of the muffins increased significantly (Pxa0≤xa00.05) the hemoglobin iron regeneration efficiency. The hemoglobin iron regeneration efficiency and apparent absorption were further enhanced by supplementing diets with orange juice or ascorbic acid. Citric acid showed no significant influence on hemoglobin iron regeneration efficiency. These results demonstrate a positive effect of baking and the presence of certain organic acids on the bioavailability of endogenous iron from wheat bran.

Nutritional Composition of British Columbia Canned Salmon

Abstract Samples of canned B ritish Columbia sockeye and pink salmon, representative of that available to consumers on a year-round basis, were analyzed for moisture, protein, lipid, ash, salt, riboflavin, niacin, pyridoxine, vitamin B 12 , vitamins A and D , calcium, phosphorus, magnesium, selenium, sodium, potassium, iron and zinc. Protein quality was assessed on the basis of amino acid composition. The sampling plan took into account species, time of season, location of catch and processing plant as factors that might influence the nutritional composition. The data are expressed as range and meanxa0±xa0standard deviation for each nutrient on the basis of species. Contents of vitamins and minerals per 100xa0g of product are also compared to the R ecommended D aily I ntakes ( RDI ) for these nutrients.

Effect of Gibberellic Acid and Ethephon on Ascorbic Acid Content And Ascorbic Acid Oxidase Activity of Redhaven Peaches

Abstract Redhaven peaches from trees treated with foliar applications of 100xa0ppm gibberellic acid or 150xa0ppm ethephon were analyzed for reduced and total L-ascorbic acid content. Reduced ascorbic acid levels were higher in treated fruit when compared to non-treated, when oxidative enzymes of the tissue had been activated by macerating the flesh. No significant differences, however, were found in either reduced or total ascorbic acid content of intact tissues. No ascorbic acid oxidase activity could be detected. It is suggested that ascorbic acid functions as a reducing agent in the fruit, retarding the effects of the oxidative enzymes. Any effect of growth regulators on the activity of enzymes such as polyphenoloxidase, might be reflected in increased quantities of reduced ascorbic acid in tissue which has undergone physical damage.

Hospital Food Quality as Affected by Freezing Rate

Abstract As frozen preprepared meals are increasingly incorporated into hospital and institution food service systems, the need arises to assess food quality as it is affected by freezing rate. Frozen precooked food quality must be assessed within the limitation of freezing equipment available to the institution. Different rates of freezing were achieved using –40°C blast-, –30° C plate- and –26°C still-air freezing. Two groups of representative precooked foods were frozen by these methods and assessed for quality after 10 and 13 weeks frozen storage by means of taste panel evaluation. Freezing rates differed significantly for the different products and freezing methods. Panel results, however, indicate no difference in food quality attributable to freezing rate, except for souffle texture which was rated significantly higher for the blast and plate frozen samples than for the still-air frozen.