Influence of watermelon seed protein concentrates on dough handling, textural and sensory properties of cookies.

Fruit processing wastes contain numerous by products of potential use in food & allied industry. Watermelon seeds represent a major by-product of the processing waste and contain high amount of nutritional proteins. Protein rich cereal based products are in demand due to their health promoting benefits. With this aim, wheat flour was fortified with watermelon seed protein concentrates (2.5 %, 5 %, 7.5 % and 10 % levels) to prepare cookies with desirable physical, nutritional, and textural and sensory properties. Substitution levels of 5 % and 10 % significantly (p ≤ 0.05) increased the dough stability and mixing tolerance index, however pasting properties and dough extensibility decreased considerably above 5 % substitution levels. Cookie fracture force (kg) increased significantly (p ≤ 0.05) above 5 % fortification levels. Cookie spread factor (W/T) increased from 2.5 % to 7.5 % fortification levels, further increase showed negative impact. Sensory scores of the cookies showed that protein concentrate may be added up to 7.5 % fortification levels. This study revealed that watermelon protein concentrates can be fortified with protein concentrates upto 5-7.5 % levels in cookies to improve their protein quality.

Total phenolics, antioxidant properties and quality of fresh-cut onions (Allium cepa L.) treated with mild-heat.

This study investigated the effect of mild-heat on fresh-cut onion slices by treating in hot water (50, 60, 70°C) for 1 min. Total phenolics (TP), antioxidant properties, colour, and weight loss of slices were evaluated during 4°C storage at 7-day intervals (21 days total). The 60°C heat treatment resulted in a significant increase in TP, from 44.92 to 52.32 mg GAE/100g. Except for 50 and 70°C treatments, TP in control and 60°C treated fresh-cut onions decreased during storage. The antioxidant properties of fresh-cut onions were 1.31, 0.99, and 62.49 µM TE/g using ABTS, DPPH, and ORAC assays, respectively. The mild-heat treatments did not affect ABTS and DPPH antioxidant activities and the colour of fresh-cut onions. The storage time had mixed effect on the antioxidant properties (ABTS decreased; DPPH and ORAC remained fairly stable). The 50°C samples exhibited the lowest weight loss during 21-day storage.

Total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh-cut mango (Mangifera indica L., cv. Tommy Atkin) as affected by infrared heat treatment.

UNLABELLED: Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh-cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh-cut cubes from 'Tommy Atkin' mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4-d intervals during 16-d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh-cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (µM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16-d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh-cut mangoes with minimal effect on the visual appearance. PRACTICAL APPLICATION: Various methods/treatments are in use for extending the quality of fresh-cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh-cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16-d storage. This is the first study reporting on the use of IR heat in fresh-cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh-cut mango cubes with minimal effect on the visual appearance.

Physicochemical, morphological and pasting properties of acid treated starches from different botanical sources.

Effect of acid modification on physico-chemical, morphological and pasting properties of banana, sweet potato, lotus stem and wheat starches were studied. Results revealed that swelling power, solubility and water binding capacity of all starches decreased by acid modification. By acid modification starch granules from different varieties tended to appear fused and less smooth than the native starch granules. The pasting properties of native starches of all different varieties have significantly decreased following acid modification. Acid modified starches showed higher syneresis as compared to native starches.

Effect of extraction parameters on curcumin yield from turmeric.

Effect of 4 independent variables - temperature (50-90°C), particle size (0.42-0.85 mm), mixing time (10-50 min) and solvent (ethanol) to meal ratio (10-50) on curcumin yield from turmeric (Curcuma longa L) was studied using central composite rotatable design. The experimental value of curcumin yield ranged between 4.49 and 12.89%. The second order model obtained for curcumin yield revealed a coefficient of determination (R(2)) of 0.78 and standard error of 0.72. The linear, square and interaction terms were significant at p <0.05 while lack of fit was non-significant at p >0.05. Surface graphs were plotted to optimize the curcumin extraction. The maximum curcumin yield was obtained when temperature, particle size, mixing time and solvent to meal ratio were 60°C, 0.42 mm, 30 min and 50, respectively.

Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology.

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60°C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43mm); extraction time (4, 8, 12, 16 and 20min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98mg/100g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R(2)) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98mg/100g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1v/w, 4, 50°C, 0.15mm and 8min, respectively.