Batters were prepared, using rice flour as the main component, and analyzed for their oil uptake properties during frying. Rice flour resisted oil absorption better but was less effective as a thickening agent than wheat flour. Of the rice components, increased amylose in the amylopectin/amylose ratio of the starch decreased the batter oil uptake, whereas increased protein content had the opposite effect. Various additives were introduced and investigated for their ability to develop viscosity and other desirable characteristics for the batter. As additives to the rice flour batters, phosphorylated starch and gelatinized rice flour enhanced both the thickening and oil-reducing capacities of the batter. Compared with values for batters from wheat flour, the percent batter oil uptake in the fried crust for the modified rice flour batters was decreased by up to 62%, and the percent total oil uptake for the whole coated drumstick was reduced by up to 59%.

Pigmented rice contains anthocyanins and proanthocyanidins that are concentrated in the bran layer. In this study, we determined the phenolic, flavonoid, anthocyanin, and proanthocyanidin content of five rice bran (1 brown, 2 red, and 2 purple) extracts. Each bran extract was evaluated for inhibitory effects on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. All purple and red bran extracts inhibited α-glucosidase activity, however only the red rice bran extracts inhibited α-amylase activity. Additionally, each bran extract was examined for their ability to stimulate glucose uptake in 3T3-L1 adipocytes, a key function in glucose homeostasis. Basal glucose uptake was increased between 2.3- and 2.7-fold by exposure to the red bran extracts, and between 1.9- and 3.1-fold by exposure to the purple bran extracts. In red rice bran, the highest enzyme inhibition and glucose uptake was observed with a proanthocyanidin-enriched fraction. Both IITA red bran and IAC purple bran increased expression of GLUT1 and GLUT4 mRNA, and genes encoding insulin-signaling pathway proteins.

Various enzymes were used to treat a protein-enriched rice flour for the production of rice protein isolates. The rice flour containing 49% protein was a by-product from the processing of brown rice for syrup production. The treatment sequence of α-amylase followed by glucoamylase was most effective, resulting in a product with 85% protein content. The product was then treated with a mixture of cellulase and xylanase, which raised the protein content in the insoluble fraction to 91%. Inorganic impurities, such as the metal manganese in the starting rice flour, were effectively removed. The recovered rice proteins, practically intact according to electrophoretic analysis, had relatively poor solubility and emulsification properties; however, these functional properties were improved substantially by adding xanthan gum as a functionalityenhancing agent.

Rice starches of long grain and waxy cultivars were annealed (ANN) in excess water at 50°C for 4 hr. They were also modified under heat‐moisture treatment (HMT) conditions at 110°C with various moisture contents (20, 30, and 40%) for 8 hr. The modified products were analyzed by rapid‐viscosity analysis (RVA), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). Generally, these hydrothermal treatments altered the pasting and gelling properties of rice starch, resulting in lower viscosity peak heights, lower setbacks, and greater swelling consistency. The modified starch showed increased gelatinization temperatures and narrower gelatinization temperature ranges on ANN or broader ones on HMT. The effects were more pronounced for HMT than for ANN. Also, the typical A‐type XRD pattern for rice starch remained unchanged after ANN or HMT at low moisture contents, and the amorphous content increased after HMT at 40% moisture content.

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Rice starch was modified with various levels of 2-octen-1-ylsuccinic anhydride (OSA). Treatments with OSA at 3, 5, and 10% resulted in starch derivatives with 0.016, 0.033, and 0.070 degrees of substitution (DS), respectively. Thermovisco properties of the derivatives were investigated by differential scanning calorimetry (DSC) and rapid visco analysis (RVA). Water content in the sample was found to have a significant effect on the characteristics of the DSC endotherm. Pasting properties of the OSA-starch and the effect of pH and salt on the RVA profiles were also studied. In general, with increased OSA-modification, the starch derivatives swelled and gelatinized at lower temperatures to achieve higher viscosities. Specifically, based on DSC analysis at 80% water, the peak temperature of gelatinization decreased from 68.5 to 63.2 degrees C as the OSA modification increased in DS from 0 (intact starch) to 0.070. On the other hand, RVA results indicate that, for samples undergoing similar increase in OSA modification, the pasting temperature decreased from 88.7 to 51.5 degrees C and the peak viscosity increased from 668 to 6822 cP.

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Reduced oil donuts are one goal of the donut industry. In this investigation, donuts were developed using wheat flour and various additives. Donut properties were analyzed including dough consistency (DC), firmness (FN), moisture content (MC), and oil uptake (OU). Replacement of wheat flour with long-grain or waxy rice flour resulted in lower DC and MC, and higher FN and OU. Replacement with gelatinized rice flour or acetylated rice starch resulted in generally higher DC, MC and FN and lower OU. Donuts formulated with wheat flour and up to 50% gelatinized rice flour were comparable to wheat donuts in general characteristics but as much as 64% lower in oil uptake.