Search

In this work, starches were extracted from four species of minor legume widely planted in China: cowpea, lentil, pea, and red kidney bean by wet milling, and their structural characteristics and physicochemical properties were analyzed and compared. The infrared spectra of all the samples presented the typical structural characteristics of starch. The starch granules had complete kidney-like or oval shape with a smooth surface. The average hydrodynamic radii of the four starches were in the following decreasing order of cowpea starch > pea starch > lentils starch > red kidney bean starch. The crystal type of pea starch was CC-type, while the crystal type of cowpea starch, lentils starch and red kidney bean starch was CA-type. The relative crystallinity of these starches was significantly different, ranging between 27.6% and 38.5%. The gelatinization characteristics varied greatly among them, all of which had high gelatinization temperature (75.3-82.8 ℃), being difficult to gelatinize. Cowpea starch was not prone to retrogradation with the lowest amylose content (26.3%), and the thermal stability of cowpea paste was best. Red kidney bean starch had the highest amylose content (31.5%) and retrogradation value, which was most prone to retrogradation. In conclusion, the four legume starches had similar granular morphology and all exhibited a C-type crystal structure, and they were similar in their retrogradation characteristics but distinct in their molecular structure and gelatinization characteristics.

BACKGROUND: Yellow mustard gum (YMG), which is extracted from the mucilaginous part of yellow mustard bran, has been considered an emerging natural hydrocolloid gum but lacks commercial development and production. To promote the commercial utilization of YMG, this study developed a pilot‐scale YMG production protocol in an economic and environmentally friendly way to produce a clean‐label YMG product. This YMG produced at pilot scale (YMW) was characterized in terms of chemical composition, rheological properties, and interaction with a commercial gum, κ‐carrageenan, and was compared with purified YMG through ethanol precipitation (YME). RESULTS: The protocol processed up to 100 L of raw material with zero solvent and a minimal number of steps and showed strong quasi‐industrial potential. The YMW showed a similar chemical composition as YME. However, the YMW contained a slightly lower amount of carbohydrate and a much larger amount of ash and potassium than the YME. The rheological results concluded that both the YMW and YME solutions exhibited shear‐thinning flow behavior and a weak gel, with YME showing higher viscosity and stronger gel structure. Most interestingly, YMW could form unpourable gels when blended with native κ‐carrageenan whereas YME barely achieved this despite the equivalent total gum concentration. CONCLUSION: This study demonstrated the feasibility of YMG production at a large scale with economic and green procedures and discovered its new functionality for commercial utilization. The gelling ability of YMG could provide it with wider applications as a result of a new potential synergistic combination. All this information should accelerate the process of full commercialization of YMG as a clean‐label functional ingredient. © 2024 His Majesty the King in Right of Canada. Journal of The Science of Food and Agriculture © 2024 Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri‐Food Canada. [ABSTRACT FROM AUTHOR]