The effect of antioxidants on butter in relation to storage temperature and duration

The effects of antioxidants on the oxidative stability of butter, under different storage time and temperature conditions, were evaluated. Natural (α‐tocopherol) and synthetic (BHA and BHT) antioxidants were added to the butter samples at two concentrations (50 and 100 ppm) immediately after the butter samples were produced from the pasteurised sweet cream, after which they were kept in the dark at 4 and ?20 °C for 6 months. Peroxide value (PV) and thiobarbituric acid (TBA) number and the residual antioxidants of the samples were examined at 30‐day intervals, starting on the second day until the end of the storage period. The measurements obtained by assaying PV and TBA number in butter samples showed that both the synthetic and natural antioxidants used were capable of protecting the butter samples against oxidation during storage at both temperatures. The butter samples with 50 ppm antioxidant could be stored for more than 180 days at 4 °C without spoilage. At ?20 °C, the addition of BHA, BHT and α‐tocopherol caused a reduction in the TBA number from 0.31 (control) to 0.21, 0.23 and 0.27 mg malonaldehyde/kg butter, respectively, and the PV decreased from 0.75 (control) to 0.46, 0.56 and 0.54 meq O₂/kg butter, respectively, after 6 months of storage. The highest residue values were determined in both the 100 and 50 ppm α‐tocopherol‐containing samples. These results indicate that α‐tocopherol exhibited a very strong antioxidant activity, which was almost equal to that of the synthetic antioxidants. Therefore, the use of α‐tocopherol is recommended as a natural antioxidant to suppress the development of rancidity in butter.     

Use of a spouted bed to improve the storage stability of wheat germ followed in paper and polyethlyene packages

Stabilization of wheat germ by heating in a spouted bed for 180–540 s with air at 140–200 °C was studied. The lipase activity decreased by 6–65%. Wheat germ processed at 200 °C for 360 s was ranked highest in sensory evaluation, described as having ‘a golden color’ and ‘nutty flavor’, and its lipoxygenase activity had decreased by 91.2%. This product and raw wheat germ were stored in paper, polyethylene and vacuum‐packed polyethylene pouches at 5 °C, room temperature (18–26 °C) and 40 °C, and the moisture contents, water activities, free fatty acid contents and peroxide values were followed for 20 weeks. The increases were faster in paper pouches than in the polyethylene ones; vacuum packaging in polyethylene did not bring about significant improvement. The peroxide values of raw samples exceeded 10 meq O₂ kg^?1 oil after 3–23 days while those of the processed samples stored at room temperature or 5 °C were still less than 10 after 20 weeks. The free fatty acid content and peroxide value changes were expressed by zero order kinetics, resulting in similar activation energies for the raw and processed samples. Copyright © 2005 Society of Chemical Industry     

Multiple-food-unit-incentive effect: Nonconservation of weight of food reward by rats.

A common assumption is that the incentive value of food is determined by weight independently of number of food units. In Experiments 1 and 2, rats trained in a T-maze with four 75-mg pellets in one alternative and a single 300-mg pellet in the other alternative developed a preference for the 75-mg pellet alternative, which did not diminish with extensive training. When the locations of the 75-mg and 300-mg pellets were reversed, rats reversed their choice of arm. Rats preferred a 300-mg pellet to four 45-mg pellets (Experiment 2) and four 75-mg pellets to four 45-mg pellets (Experiment 3). Thus, rats prefer multiple- to single-food units; this effect is permanent rather than temporary, and the incentive value of food is not determined by weight of food alone or number of food units alone. Rats may count food units, judging a given weight of food as greater the greater the number of units—a failure of conservation common, possibly, to a number of species from birds to humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Production of bread crumbs by infrared-assisted microwave drying

This study is aimed to investigate the possibility of using infrared-assisted microwave drying for production of bread crumbs and to determine drying conditions in halogen lamp-microwave combination oven to produce bread crumbs with the highest quality. Bread crumb dough were dried from about 40.9 to 8% moisture content by conventional, microwave, infrared and infrared-assisted microwave drying separately and in combinations. Halogen lamp and microwave power levels of 30, 50 and 70% were used. Percent reduction in the drying time were 80.2–94.0 for infrared, 96.5–98.6 for microwave and 96.8–98.6 for infrared-assisted microwave drying. ΔE values were lower in microwave drying and higher in infrared drying. Infrared-assisted microwave dried crumbs generally had similar color values with the conventionally dried ones. Effect of power on color change was not observed. All drying methods were found to be effective in increasing water binding capacity, which increased with microwave power in microwave drying but the influence of halogen lamp power was not seen in infrared drying. At fixed microwave (halogen lamp) powers increase of halogen lamp (microwave) power did not affect the water binding capacity in infrared-assisted microwave drying.     

Comparison Study of Microstructure and Phase Evolution in Mg-Nd- and Mg-Gd-Based Alloys

Microstructure and phase evolution in Mg-Nd-, Mg-Gd-, and Mg-Gd-Nd-based alloys with additions of Zn, Zr, and Y were analyzed in the as-cast, solution-treated and aged conditions. Close similarity between the as-cast microstructures and precipitation sequence during aging was revealed. Along with this, distinct features of eutectic compounds and of crystal structure, composition, and orientation relationships of β″, β′, and β ₁ phases were established. Formation of Zn₂Zr₃ rods in Mg-Nd-based alloy and cuboid-shaped particles in Mg-Gd- and Mg-Gd-Nd-based alloys is discussed. The features of the age hardening curves were connected with differences between β″ → β′ transformation and different diffusivities of Gd and Nd in Mg-matrix.     

Separation of bread wheat flours into starch and gluten fractions: effect of water temperature alone or in combination with water to flour ratio

Two different commercial bread wheat flours (BF‐I, 65% extraction and BF‐V, 86% extraction) were separated into gluten and starch milk by making a dough, allowing some time for maturation, dispersing the dough in water and wet sieving/washing. The effect of using of warm water (20–45 °C) for dough making and washing on separation was studied for BF‐I flour at 640 g kg^?1 water to flour ratio of and 300 s maturation time, and the separation was found to improve with increase in temperature. The combined effects of water temperature (20–50 °C) and water to flour ratio (640–780 g kg^?1 for BF‐I and 620–870 g kg^?1 for BF‐V) were studied at 600 s maturation time. The quantities and dry matter contents of the gluten fraction and starch milk were measured; a sample of starch milk was centrifuged to obtain decantate, tailing and prime starch fractions, and the dry matter contents of each were determined. All the dried samples were also analysed for protein content, and the fractional recoveries of dry matter and protein in the gluten fraction, prime starch, tailings and decantate were calculated. The results indicated the optimum point for BF‐I flour to be the combination of optimum farinograph water absorption and 40 °C. BF‐V showed very poor separation behaviour within the ranges studied. At the optimum farinograph water absorption the use of warm water for dough making and 20 °C water for washing steps was also tried, but no significant improvement over the 20 °C results was obtained. © 2002 Society of Chemical Industry     

Shrimp waste extract and astaxanthin: rat alveolar macrophage, oxidative stress and inflammation

Astaxanthin is a carotenoid known to have antioxidant and antiinflammatory properties. This study examined if shrimp astaxanthin modulates the production of superoxide (O(-)(2)), nitric oxide (NO), and tumor necrosis factor-α (TNF-α) in rat alveolar macrophages. The oxidative effect was induced by phorbol myristate acetate and lipopolysacharide. The treatment was compared with superoxide dismutase, butylated hydroxytoluene, commercial astaxanthin, N-nitric-L-arginine methyl ester and L- canavanine, all administered as a 43.5-μg/mL dose in the presence of 1% EtOH/0.5% DMSO. All treatments maintained cell viability, as observed in the MTT assay, and shrimp extract increased the viable alveolar macrophages to 168%. Shrimp extract and commercial astaxanthin showed a suppressive effect on the generation of both free radicals O(-)(2) and NO, while purified shrimp astaxanthin was specific to NO. TNF-α secretion was correlated with NO production. However, in this correlation, the shrimp extract completely inhibited TNF-α. In the light of these findings, the antioxidant action demonstrated in this study suggests that the shrimp extract could be considered as a promising source of bioactive substances with antioxidant and anti-inflammatory activity. PRACTICAL APPLICATION: The hydrolysis process of shrimp waste generates bioactive products that add economic value to shrimp processing, mainly because they may have applications in nutraceutical and animal feed industry.