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  • Author or Editor: B. Singh x
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Germinated brown rice received great attention as healthy ingredient and can be used as an alternative source in the malting and brewing industry. The germination capacity, physico-nutritional properties, sugars, and diastase enzyme activity of brown rice affected by germination times and temperature were determined and compared with control. Soaking in water increased the moisture content of brown rice. Germination rate of brown rice was also increased by higher germination time and temperature and reached maximum after 48 h of germination at 35 ºC. However, dry matter loss, grain weight, and density are affected to a lesser extent. Germination significantly (P<0.05) affects the crude protein, fat, fibre, and ash contents. Total carbohydrates content showed linear relationship with germination time and temperature. During germination, hydrolytic enzymes act on starch, reducing its concentration and resulting in higher total and reducing sugars amounts. Increase in germination time and temperature also increased diastase enzyme activity.

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The application of ultrasound during extraction of oil from apricot kernels using hexane was evaluated and compared with conventional methods (mechanical extraction and Soxhlet extraction). Results show that ultrasound assisted extraction (UAE) yields more oil with less solvent consumption. The oil yield from UAE, SE, and ME were 44.72%, 44.33%, and 35.06%, respectively. It is noteworthy that it took 44 min to extract oil by UAE method, while alike yield was obtained from SE in 6 hours. Oil extracted by UAE exhibited significantly higher peroxide and ester values. The functional groups of apricot kernel oil were analysed using Fourier transform infrared spectroscopy. Untreated and treated kernel powders were studied by scanning electron microscopy, and the development of microstructures and disruption of cell walls were evaluated. Our study suggests that ultrasound assisted extraction may be an effective method to extract edible oils by achieving higher efficiency in shorter extraction time.

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Abstract

Brown rice was germinated for different times (12, 24, 36, and 48 h) at different temperatures (25, 30, and 35 °C) with the aim to improve the in vitro digestibility and antioxidant potential of the flour made from it. Results showed that increase in germination time and temperature increased in vitro digestibility of starch and protein during germination of brown rice owing to depolymerisation of starch and protein molecules by enzymatic activity. After germination under varying conditions, antioxidant activity increased from 50.19 to 95.58%, total phenolic and flavonoid contents from 0.88 to 2.02 mg GAE/g and 34.06–62.94 mg QE/100g, respectively. Germination at elevated temperature (35 °C) for prolonged time (48 h) also increased the reducing power by 60.49% and metal chelating activity by 114.50% as a result of structural breakdown of bound phenolics. Increased activity of hydrolytic enzymes with progress in the germination time and temperature also results in continuous reduction in the pasting properties and lightness values (L), while increasing a* and b* values of the flour of germinated brown rice. Tailored germination, therefore, can be offered as a tool to increase nutrient digestibility and bioactive potential of brown rice as compared to non-germinated brown rice, thus, producing naturally modified flour with enhanced functionality.

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Sunflower (PSH 569) was used to obtain textured defatted meal. Proximate analysis, water absorption index (WAI), water solubility index (WSI), fat absorption capacities (FAC), foaming capacity (FC), and bulk density (BD) were determined. The objective of the study was the optimization of extrusion conditions for production of textured defatted sunflower meal using response surface methodology (RSM) by evaluating functional properties. It was dried, grinded, and sieved to eliminate hull and fibre. Numerical optimization provided eight solutions with desirability value varying from 0.81 to 0.82. Range of predicted values of FAC (80.96–90.49), WHC (1.95–2.12), WSI (3.22–3.36), WAI (2.84–3.08), bulk density (0.31–0.36), and foaming capacity (14.39–16.30) were used for numerical optimization. Best extrusion conditions were 16.36% feed moisture, 300 r.p.m. screw speed, and 149.40 °C barrel temperature. Textured sunflower defatted meal was prepared using the above optimized conditions.

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In this study honey samples of Eucalyptus honey (Eucalyptus lanceolatus) were botanically characterized. Response surface methodology was used to analyze the effect of temperature, time and pH on the quality responses (hydroxymethylfurfural concentration and diastatic activity) of Eucalyptus honey. A central-composite rotatable design was used to develop models for the responses. At the central value of time (10 min), the maximum concentration of hydroxymethylfurfural was demonstrated at the highest temperature and pH. The maximum value of hydroxymethylfurfural concentration was also obtained at the maximum time and temperature, while keeping the pH at the central value of 5.3. Diastatic activity decreased as the pH moved away from the central pH value of 5.3 to 5.6 at any level of temperature and time. Three-dimensional response surfaces were superimposed, and the overlapping regions gave the diastatic activity (calculated as diastase number 9 to 23.09 °G) and hydroxymethylfurfural concentration (3 to 10.21 mg kg-1) at 48±1 °C for 9.5±1 min at 5.15±0.15 pH.

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