One Pot Cooking of Rice Grains for Preparation of Rice-Gel Samples Using a Small-Scale Viscosity Analyzer

Abstract

Rice-gel prepared by the following three steps: rice grain cooking, shearing of the cooked rice, and cooling for gel formation, is expected as a novel food ingredient for modification of various food products such as bread and noodles. To meet the demand for high-throughput systems for research and developments on the new rice gels, herein we established a mini-cooking system for preparation of rice gel samples from grains using a small-scale viscosity analyzer (Rapid Visco Analyzer; RVA). Polished rice grains (4 g) were cooked with 22 mL of water in a canister, and the paddle equipped in the canister was rotated at 2,000 rpm for 30 min (80 °C was used as a representative) to shear the cooked rice. The sheared paste was cooled to 10 °C at 160 rpm, and the initial gelation property was evaluated by viscosity analysis within the RVA. Alternatively, the sheared paste was transferred to an acrylic mold and kept at 4 °C for 0, 1, 3, and 5 days for determination of the hardness with a compression test. Compressive forces required to penetrate 20 % thickness for three tested rice cultivars were measured, and the trend of the value shifts during preservation is similar to the corresponding trend obtained in 300-g grain scale laboratory tests, whereas the individual values were halved in the former. This small cooking method could offer a useful assay system for a rapid evaluation in the breeding programs and in the high-throughput screening of additives for the modification of properties.

Characterization of the Interactions between Cereal Flour and “Nata Puree” in Batter

“…Static flour gelatinization results in formation of a starch network, whereas high-speed shearing of rice gel modifies its rheological properties by reconstructing the gel network, suggesting that the rheological properties of statically gelatinized rice flour could be further modified by mechanical shearing after gelatinization. 20) Another way of controlling gel properties would be the addition of gel-forming ingredients such as agar and gelatin; NP might also disperse powdered ingredients, and the static gelatinization step for flour would also gelatinize said powders, as shown in a suspension with curdlan powder. 7) For reproduction of various foods by automatic cooking, a great deal of effort would be required to automate various conventional cooking processes.…”

Development and performance analysis of continuous cooking systems

“…As for cooking advances, rice swelling occurs owing to moisture absorption, and gelatinization of starch contained in rice grain was successfully predicted using swelling particle kinetics. Specifically, the gelatinization process occurs at the interface between cooked and uncooked rice (Matsuki et al, 2019; Rather et al, 2016). The image analysis technique was also employed innovatively to evaluate the progress of rice cooking by calculating the variation in the proportion of uncooked and cooked regions over time.…”