SENSORY QUALITY OF READY‐TO‐EAT LETTUCE WASHED IN WARM,CHLORINATED WATER1

Three prepackaging treatments were evaluated for ready‐to‐eat (RTE) lettuce. Fresh iceberg lettuce pieces were dipped for 3 min in cold water (4C) with 100 ppm total chlorine, warm (47C) water with 100 ppm chlorine and tap water at room temperature. The lettuce was dewatered by centrifugation, packed in breathable film bags (OTR: 1600‐2000 cc/m²/24 h) and stored for 11 days at 1C. Sensory evaluation revealed that the texture and visual appearance of stored RTE lettuce were improved by the warm water treatment. However, heat processing induced changes in the flavor of the lettuce, and a chlorinaceous off‐odor was detected by some panelists.     

WHEAT BRAN (TRITICUM AESTIVUM): COMPOSITION, FUNCTIONALITY AND INCORPORATION IN UNLEAVENED BREAD

High fiber Chapathi, an Indian unleavened bread incorporating different levels (5–15%) of wheat bran to wheat flour was prepared and evaluated for acceptability and farinograph characteristics. Whole wheat flour, wheat bran and its differently milled fractions were analyzed for chemical composition and functional properties. The water absorption capacity of bran was slightly lower than that of flour and did not increase as a function of time. The bran incorporated doughs were difficult to knead and sticky with no change in rolling properties. Farinograph characteristics revealed an increase in dough development time and a decrease in mixing tolerance index as the level of incorporation of bran increased. Wheat bran incorporated products scored lesser for the sensory quality attributes than controls. The differences were statistically significant for products prepared with 10% and 15% bran and not significant for products prepared with 5% level of bran. It can be concluded that wheat bran can be incorporated up to a level of 5% for preparation of high fiber phulkas or chapathis without affecting sensory quality.     

Antioxidant Extracts from Acorns (Quercus ilex L.) Effectively Protect Ready‐to‐Eat (RTE) Chicken Patties Irrespective of Packaging Atmosphere

This study evaluated the impact of a phenolic‐rich acorn extract (200 ppm gallic acid equivalents) and the concentration of oxygen in the packaging system (low‐oxygen modified atmosphere; 5% vs. normal‐oxygen; 21%) on lipid and protein oxidation and consumers acceptance of the ready‐to‐eat chicken patties. Samples were subjected to cooking (electric oven, 170 °C/16 min), cold storage (14 d at 4 °C), and reheating (microwave, 600 mW/1 min). Samples treated with acorn extract kept thiobarbituric acid‐reactive substances numbers and lipid‐derived volatiles at basal levels throughout the whole processing irrespective of the oxygen concentration in the packaging atmosphere. Consistently, treated patties had lower protein carbonyls than control ones. The acorn extract also controlled color and texture deterioration during chilled storage and reheating and improved the color and odor acceptance of the products. Formulating with acorn extract is a feasible strategy to inhibit the oxidation‐driven changes and preserve the quality of reheated samples as if there were freshly cooked. Compared to the effect of the antioxidant extract, the concentration of oxygen in the packaging system was negligible in terms of quality preservation.     

L-ASPARTYL-L-PHENYLALANINE METHYL ESTER (ASPARTAME) AS A SWEETENER

In aqueous solutions, L-aspartyl-L-phenylalanine methyl ester (aspartame) was 182 times sweeter than 2% sucrose but only 43 times sweeter than 30% sucrose according to rank analyses of scores from 20 judges. In buffer solutions (pH 3.2), pH was elevated by 0.025% and 0.12% aspartame and not by 4% or 12% sucrose, but no effect on sweetness equivalents or sourness was detected. Sweetness of 0.025% aspartame was enhanced by gelatin (1.5%) and methocel (1%). Enhancement also occurred when gelatin was combined with 0.12% aspartame. Sweetness ranks were not significantly affected by 1% carboxymethylcellulose or gum arabic. Viscosity was not a reliable indicator of differences in sensory response for thickness.     

2,4,5-TRIHYDROXYBUTYROPHENONE (2,4,5-THBP) AS A SUBSTRATE FOR HORSERADISH PEROXIDASE1

2,4,5-trihydroxybutyrophenone (2,4,5-THBP), in the presence of hydrogen peroxide (H₂O₂), is a substrate for horseradish peroxidase (HRP) with a Km value of 2.5 mM. An intermediate red product(s), probably 2,4,5-THBP quinone, characterized by a peak at 490–500 nm, was detected and the time course of its conversion to the final red product(s) was studied. The relationships between the rate of 2,4,5-THBP oxidation to pigmented product(s) as a function of various concentrations of H₂O₂, 2,4,5-THBP and HPR are described.     

2,3,4-TRIHYDROXYACETOPHENONE (2,3,4-THAP) AS A SUBSTRATE FOR MUSHROOM TYROSINASE1

2,3,4-Trihydroxyacetophenone (2,3,4-THAP) can serve as a substrate for mushroom tyrosinase with a K_m value of 1.2 mM. The product(s) formed is yellow, characterized by a peak at 420–430 nm. A lag period in 2,3,4-THAP oxidation to the yellow product(s) in the presence of ascorbate indicates that the initial product(s) is an o-quinone of 2,3,4-THAP. An oxime, characterized by a broad peak at 510–650 nm, is the likely product formed between o-quinone of 2,3,4-THAP and NH₂OH. The ?_m of the o-quinone of 2,3,4-THAP was estimated to be 1.6 × 10⁴ M^?1 cm^?1 at 425 nm. During relatively long incubation periods, the peak of the yellow product(s) shifts from 420–425 nm to 430–440 nm; the solution remains yellow and transparent for at least a week and no precipitate is formed. The final yellow product(s) is probably a low molecular weight polymer of THAP-o-quinone (dimer, tetramer, etc).     

Chemical Acylation of Water‐Soluble Antioxidant of Bamboo Leaves (AOB‐w) and Functional Evaluation of Oil‐Soluble AOB (cAOB‐o)

Antioxidant of bamboo leaves (AOB) is a novel natural food antioxidant approved in China since 2004. Natural phenolics contained in the current AOB are usually polyhydroxy derivatives exhibiting hydrophilic character, which has been marked as water‐soluble AOB (AOB‐w). In order to broaden the application fields, oil‐soluble AOB (cAOB‐o) was obtained by chemical acylation of AOB‐w with different chain‐length fatty acids varying from C8 to C18. Results indicated that the yield and solubility of cAOB‐o in 1‐octanol solvent depended on the carbon chain length of acyl donor, and cAOB‐o derived from C12 fatty acid exhibited the more powerful antioxidant activity evaluated by β‐carotene/linoleic acid bleaching assay. Total phenolic content decreased by Folin–Ciocalteu assay. Fourier transform infrared spectra showed the increase of a carbonyl (C = O) peak at 1701 cm^?1 and a decrease in the intensity of the absorption at 3400 cm^?1 (O‐H stretching) in cAOB‐o. Acylation was inferred to mainly occur on the hydroxyl groups of flavones C‐glycosides according to the change of high‐performance liquid chromatography spectra and the contents of total flavonoids and phenolic acids. cAOB‐o with the addition of 0.02% significantly increased oxidative stability of palm oil 1.59 times, lard 3.74 times, and fried potato chips 2.08 times, which was better than the effect of oil‐soluble tea polyphenol (P < 0.01). Moreover, cAOB‐o was identified to be actually nontoxicity by an acute oral toxicity test. All the above results indicated that cAOB‐o could be used as a novel and effective oil‐soluble antioxidant in the food industry.     

Cyclodextrin and methacrylic acid octyl phenols poly(ethylene oxide) ester‐induced synergistic effect in a novel poly(AM‐co‐A‐β‐CD‐co‐AE) polymer

Owing to superior properties such as temperature resistance and salt tolerance etc., modified polyacrylamide (PAM) as one of the main injected polymers has been widely investigated to enhance oil production in reservoirs. Herein, a novel poly(AM‐co‐A‐β‐CD‐co‐AE) polymer was synthesized by utilizing β‐CD and AE to copolymerize with AM and characterized by FT‐IR and SEM. Furthermore, the temperature resistance and salt tolerance of poly(AM‐co‐A‐β‐CD‐co‐AE) polymer were explored. The results showed that the presence of the poly(AM‐co‐A‐β‐CD‐co‐AE) polymer better achieved temperature resistance and salt tolerance properties than is the case with PAM, which has potential application for enhancing oil recovery in the high‐temperature and high‐mineralization oilfield. On the other hand, the inhibition performance of poly(AM‐co‐A‐β‐CD‐co‐AE) polymer as a corrosion inhibitor was evaluated by SEM and electrochemical techniques. SEM observations of the carbon steel surface confirmed the protective role of the corrosion inhibitor. The results of potentiodynamic polarization and EIS measurements on the corrosion inhibition of carbon steel samples in 0.5 M sulfuric acid solutions revealed that the highest inhibition efficiency of it over 90% was obtained, indicating poly(AM‐co‐A‐β‐CD‐co‐AE) polymer acts as a more efficient corrosion inhibitor for carbon steel.