ANTIOXIDANT POTENTIAL OF TEMPEH AS COMPARED TO TOCOPHEROL

SUMMARY –The antioxidant potential of tempeh to preserve tocopherol-stripped corn oil was studied. Different levels of tempeh were mixed into corn oil, and incubated at 37°C for a maximum of 6 wk. Peroxide values were determined biweekly. Results showed that tempeh can prevent lipid oxidation. Corn oil containing 50% tempeh showed higher antioxidant potential than those containing 25% tempeh, 0.01%α-tocopherol, or 0.03%α-tocopherol. This study substantiates the antioxidant potential of tempeh and suggests its use with other foodstuffs to help preserve the lipids contained therein.     

Temperature Acclimation and Its Effects on Porcine Muscle Properties in Two Humidity Environments

SUMMARY— The effects of temperature and humidity on postmortem and associated muscle properties during growth of "stress susceptible" pigs were evaluated. Exposure to ambient temperatures of 32 and 21°C for alternating 3-day periods caused rapid post-mortem glycolysis, high percent light reflectance, and increased light to dark fiber ratios in the longissimus dorsi muscle as compared to constant (27°C) temperature, but only in moderate (38–42% relative) humidity environments. The above events due to temperature acclimation were masked when the humidity was low (17–23% relative). Humidity effects that were independent of temperature acclimation resulted in high percent light reflectance and high muscle temperature in the post-mortem muscle of pigs reared in low humidity. No significant differences were found in lactic dehydrogenase or succinic dehydrogenase enzyme activities of longissimus dorsi or gluteus medius muscles.     

The Application of Colour Measurement

Earlier review papers by Hunt [I] and McLaren [2] have dealt with the basic principles of colour measurement and its application to the measurement of colour difference, respectively. This paper is mainly an attempt to assess the present situation on instrumental recipe prediction, but it also includes topics such as whiteness and fluorescence, metamerism, blends of coloured fibres, and the production of colour-separation transparencies in printing. Colour differences are used at various stages of the recipe prediction procedure.     

Sensory and functional properties of cheese: incorporation of whey proteins by pH manipulation and heat treatment

The effect of pH manipulation prior to high heat treatment on the effectiveness of whey protein denaturation in milk for cheesemaking has been studied. It has been found that the severity of heat treatment of milk required for denaturation can be reduced if the pH is altered during heating. The sensory and functional properties of cheddar-type cheese produced for high heat treated milk can be improved by manipulation of pH on heat treatment of milk.     

Inhibition of Lipid Oxidation in Meats by Inorganic Phosphate and Ascorbate Salts

The sodium salts of tripolyphosphate, tetrapyrophosphate, L-ascorbate monophosphate, and L-ascorbate polyphosphate at 0.3% and L-ascorbic acid and sodium L-ascorbate at 0.1% were added to ground turkey and ground beef. Sensory attributes and hexanal content were evaluated immediately after cooking and after 1 and 3 days storage (4°C). Percentages of moisture and fat and nonheme iron were determined. All samples containing a phosphate salt had more meaty flavor and less stale and rancid flavor and aroma and contained less hexanal after 3 days storage than samples with no additive. The addition of phosphate salts decreased cooking losses but did not affect fat content. Phosphate salts decreased nonheme iron in cooked turkey patties but not in beef patties. The taste panel detected a very slight soapy flavor in patties with the addition of any phosphate salt at 0.3%.     

Sensory Attributes and Instron Measurements of Reduced-Nitrite Poultry Frankfurters With Sorbic Acid or Potassium Sorbate

Poultry frankfurters (0 and 40 ppm nitrite) with sorbic acid or potassium sorbate were studied. Flavor characteristics were influenced by nitrite but not by ascorbic acid or potassium sorbate. Frankfurters with sorbic acid were softer and those with potassium sorbate were firmer than those without. Nitrite alone increased firmness. Sorbic acid appeared to counteract that increased firmness and potassium sorbate enhanced the increase in firmness when those compounds were used in combination with nitrite in the poultry frankfurters. Simulated-teeth attachments for the Inston gave results similar to sensory firmness scores. Frankfurters with sorbic acid added had lower pH than frankfurters from other treatments.     

Palatability and Selected Related Characteristics of Three Types of Roasted Porcine Muscle

SUMMARY: A completely randomized design was followed to evaluate 48 roasts posterior third of the loin) from 12 Duroc and 12 Poland China barrows. Antemortem treatment of pigs produced "normal", pale-soft-exudative (PSE) and dark-firm-dry (DFD) longissimus dorsi (LD) muscle. Meat was roasted at 350°F to an internal temperature of 167°F and evaluated by organoleptic and selected objective measurements. There was no significant organoleptic preference for one type ("normal", PSE, DFD) of LD. Also, differences among types of muscle were not significant for roasting time, volume of press fluid or total moisture (press method); whereas roasting losses, total moisture (Brabender) and pH of LD were affected significantly by type of muscle. In general, there were significant ( P < 0.05) differences between PSE and DFD muscle, and between "normal" and DFD muscle. DFD muscle exhibited the smallest roasting loss and greatest total moisture, whereas PSE muscle had the greatest roasting loss and least total moisture. DFD muscle rated highest in pH and lowest in Warner-Bratzler shear value. LD from Durocs was more tender ( P < 0.05), had a higher ( P < 0.05) pH, and contained less (P < 0.01) total moisture (Brabender) than LD from Poland Chinas. Cooking losses were greater (P < 0.05) for roasts from Durocs than for roasts from Poland Chinas.     

Fourier-transform infrared spectroscopy study of an organic–mineral composite for bone and dental substitute materials

A new injectable biomaterial for bone and dental surgery is a composite consisting of a polymer as a matrix and bioactive calcium phosphate (CaP) ceramics as fillers. The stability of the polymer is essential in the production of a ready-to-use injectable sterilized biomaterial. The purpose of this study was to detect possible polymer degradation which may have been caused by the interaction with the fillers using Fourier transform infrared spectroscopy. Composites containing CaP fillers (biphasic calcium phosphate, hydroxyapatite and peroxidized hydroxyapatite) and polymer (hydroxypropyl methyl cellulose) were prepared. To investigate the properties of the polymer, the inorganic and organic phases of the composite were separated using several extraction methods. The difficulty in separating the organic (polymer) from the mineral (CaP fillers) phases in the composite investigated in this study suggested the presence of strong interactions between the two phases. Spectra of extracted polymers showed new absorption bands of low intensities and indications that some chemical modifications of the original polymers have occurred. Results also indicated that the filler composition has an effect on the integrity of the polymer.