Technological properties,in vitro starch digestibility and in vivo glycaemic index of bread containing crude malva nut gum

The effects of crude malva nut gum (CMG) on the texture, digestion and the glycaemic index (GI) of white bread were investigated. Different CMG levels (0%, 2.5%, 5%, 7.5% and 10% w/w based on weight of flour) were added into a bread formula. The lightness (L*) and loaf‐specific volumes of the bread decreased with increased CMG levels. Firmness of the bread increased with increased CMG content. The in vitro starch digestion kinetics showed that bread containing CMG had generally lower predicted GI (74–81 vs. the control). In vivo human testing showed that increasing the CMG reduced the GI of the bread. The GI values of bread containing CMG ranged from 73 to 98 of the control. Overall liking scores of consumers ranged between ‘like slightly’ and ‘like moderately’ (6.1–7.1) compared to 7.1 for the control. Thus, the addition of CMG in carbohydrate‐based foods may lower the GI.     

Sensory Optimization of Broken-Rice Based Snacks Fortified with Protein and Fiber

ABSTRACT:  A 3-component mixture experiment was used to optimize the formulation of broken-rice based snack fortified with protein and fiber based on consumer sensory acceptability. Soy protein isolate and guar gum were used as a good source of protein and fiber, respectively, according to DRV (daily reference value) based on a 2000-calorie diet. A consumer panel evaluated sensory acceptability of color, crispness, and flavor, and overall liking of 12 experimental broken-rice based snack formulations. Predicted models derived from the restricted nonintercept regression analysis were used to plot mixture response surfaces (MRS) of each sensory attribute. Areas within the MRS plots having predicted acceptability scores of at least 6.5 (on a 9-point hedonic scale) for color, crispness, flavor, and overall liking were selected to derive a predicted optimum formulation range. Flavor acceptability was a limiting factor in attaining the optimum formulation range, which consisted of 40% to 48% broken-rice flour, 8% to 16% guar gum, and 20% to 33% soy protein isolate. To verify the obtained predicted models, the formulation containing 48% broken-rice flour, 8% guar gum, and 20% soy protein isolate, which was located in the optimum area, was chosen to support our effort to utilize and add value to broken rice. Selected physicochemical measurements of the chosen optimized formulation were determined. One serving size (30 g) of the chosen optimized snack product provided 6.58 g protein and 3.80 g dietary fiber, which met the US FDA definition of a good source of protein and dietary fiber.     

Effects of thermal processing on antioxidant activities,amino acid composition and protein molecular weight distributions of jasmine rice bran protein hydrolysate

This research aimed to evaluate the effects of thermal processing on the amino acid composition, molecular weight distribution (MW) and antioxidant activities of Jasmine rice bran protein hydrolysates (JBH). JBH was prepared by enzymatic hydrolysate (alcalase and flavourzyme at a ratio of 9.81:90.19, 2.84% w/w) for 60 min. JBH samples were treated as follows: non-heat (NJBH), pasteurisation (72ºC, 15 min; PJBH) and sterilisation (121ºC, 15 min; SJBH). For SJBH treatment, the browning index and fluorescence intensity increased (P < 0.05). FTIR showed that thermal process changed the intensities and location of some bands. Thermal processing affected MW by decreasing it from high MW (>10 kDa) to medium (3–10 kDa) and low MW (<3 kDa). Val, Met, Ile and Leu contents increased after thermal processing. Compared with NJBH, the IC₅₀ values of ABTS and FRAP of SJBH were not significantly different, while the IC₅₀ of DPPH increased (P ≥ 0.05).