Broken rice kernels and the kinetics of rice hydration and texture during cooking

Corner coil heating mode improves the matrix uniformity of cooked rice in an induction heating cooker

Nowadays, an increasing number of people worldwide use induction heating cookers to cook rice for consumption. This work reveals the influence of induction heating cooker heating modes on the quality attributes of cooked rice. Three heating modes, including bottom coil heating mode (mode 1), corner coil heating mode (mode 2), and side coil heating (mode 3), were used. Among the three modes, mode 2 allowed for an intermediate heating rate during rice cooking. For mode 2, the minimized temperature difference between the upper layer (including the central upper layer and peripheral upper layer) and the lower layer (including the central lower layer and peripheral lower layer) can reduce the effect of water absorption time difference on rice quality. Consequently, the rice cooked using mode 2 exhibited improved matrix uniformity, as indicated by the similar moisture content (59.92–61.89%), hardness (15.87–18.24 N), and water mobility (the relaxation time and peak area of the third relaxation peak) of rice samples at four different positions in the pot. The rice cooked by mode 2 showed better texture appearance and a more uniform porous microstructure. Consistently, the cooked rice samples by mode 2 at different positions did not show substantial differences in their starch digestion features.

A broken market: can increased access to broken rice decrease food insecurity in Haiti?

Haiti is a unique rice market in the sense that, despite the high poverty rates and dependency on rice as a staple, it relies on imports (80% of total consumption) of high-quality milled rice for which it pays a premium price. Haiti requires that all imported rice have a maximum of 4% broken kernels, which results in Haiti importing one of the most expensive non-fragrant long grain rice in the world. This study implements a non-hypothetical field experiment (300 observations) to elicit which rice attributes Haitians valued as revealed by their purchasing behavior in an open-air market setting. Specifically, we set out to estimate if Haitians would discount broken rice in such a manner that strict import regulations, which keeps cheaper imported broken rice out of domestic markets, continue to be warranted. Our findings suggest consumers (across locations and income groups) were not found to pay more for a reduced amount of broken rice, with the exception of the highest income group. This should signal to policy makers in Haiti that consumers are willing to consume rice with a higher percentage of brokens than the 4% importation standard. This is important from a food security standpoint as rice with a higher broken percentage provides the same nutritional value as rice with a lower broken rate, and can be sourced globally at a discounted price. Allowing imports of rice with higher broken rate could help alleviate food insecurity in Haiti by providing a cheaper alternative to relatively expensive domestic rice and imported rice, which currently has an inflated price due to its high-quality standards imposed by Haitian importers.

US Consumers' Perceptions of Raw and Cooked Broken Rice

Rice supplies about 20% of the calories to the world’s consumers. Milling removes the outer husk and bran, breaking about 20% of the rice kernels during the milling process that equates to almost 100,000,000 tons of rice annually. Broken rice is discounted in price by almost half or relegated to non-human consumption. This study seeks to understand why this large percentage of rice production is discounted for human consumption. Consumers who routinely consume rice evaluated raw and cooked rice with 5%, 10%, 20%, 30% and 40% levels of brokens. Sensory analysis indicated the appearance of raw rice with high levels of brokens affected the price consumers were willing to pay. Panelists were not able to discern sensory differences amongst cooked rice samples with different brokens percentages despite an eight-fold difference in brokens (p < 0.01). From this, we concluded that the price discounts imposed on broken rice are not because of perceived differences in the eating quality of cooked rice. Overall impression and overall texture were the two most significant determinants in willingness to purchase rice. The five cooked-rice samples with different levels of broken rice inclusion did not differ in terms of willingness to purchase.

Broken rice grains pregelatinized flours incorporated with lyophilized açaí pulp and the effect of extrusion on their physicochemical properties

Liophilized açaí pulp (LAP), which is considered a power food, could enrich broken rice grains flours (BRG), which is an abundant by-product in many countries. The extrusion could change the physico-chemical properties of this mixture, which later could be applied in the development of instant food products, as an appeal regarding the appearance, nutritional value and the presence of bioactive compounds. This study examined the effect of LAP incorporation (0, 5, 10, 15, and 20%) on the physical, chemical, and functional properties of BRG pregelatinized flours at mild extrusion conditions. Extrusion significantly changed the solubility and absorption of water, the thermal and pasting properties of pregelatinized flours. DSC analysis did not show gelatinization peaks after extrusion, indicating a total gelatinization of the starch. Extrusion also affected the color and chemical composition, and to a greater extent, the anthocyanin content, the phenolic compounds and the antioxidant capacity, despite the mild process conditions. The mixture with 10% LAP resulted in a product with a reddish color, rich in fiber and presented lower loss of anthocyanin (27.16%), therefore, the most suitable to be used as an ingredient in the preparation of ready-to-eat foods with higher functional value.

Effects of incorporating nonmodified sweet potato (Ipomoea batatas) flour on wheat pasta functional characteristics

The effects of substituting wheat flour using fractions of blanched or nonblanched sweet potato flour on produced pasta functional characteristics were investigated. The use of sweet potato flour to replace fractions of wheat flour, regardless of blanching treatment, resulted in significant (p < .05) increase in water holding capacity (WHC), cooked pasta water uptake and solid leaching out and freeze-thaw stability of produced pasta. For instance, treatment containing 40% of nonblanched sweet potato flour and held at 55C resulted in 27% point increase in WHC compared to the control. Sweet potato flour was also contributed to the decrease in treatments pasting viscosities and in cooked pasta hardness. Cooked pasta hardness was significantly (p < .05) decreased from 255.6 N to 187.5, and 152.6 N when using 15% blanched and 40% nonblanched sweet potato flour replacements, respectively. Flow behavior index of wheat flour treatments containing fractions of sweet potato flour were fitted in a shear thinning model. Quality indices of pasta made using fractions of sweet potato were equivalent to or sometimes superior to that of the control sample. Results indicated the possible enhancement of pasta nutritional quality including firmness, cooking loss, and water uptake without impairing consumer acceptability.

PRACTICAL APPLICATIONS

The use of sweet potato flour in pasta would enhance the nutritional and physicochemical properties of developed pasta and pasta products. Furthermore, since sweet potato is not cultivated most of the year; sweet potato flour pasta would be better utilized in food processing and is expected to enhance sweet potato consumption year around.