Changes in Morphological and Physicochemical Properties of Waxy and Non-waxy Proso Millets during Cooking Process

Qinghua Yang,Long Liu,Jing Li,Baili Feng,Xiaoli Gao,Weili Zhang

doi:10.3390/foods8110583

Qinghua Yang, Long Liu + Show 4 more

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https://doi.org/10.3390/foods8110583

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Abstract

Proso millet, a grain which is principally consumed in cooked form, is favored by consumers because of its rich nutritional value. However, the changes in morphological and physicochemical properties of proso millet grains occurring during the cooking process have rarely been reported. In this study, we investigated the changes in morphological and physicochemical properties of cooked waxy and non-waxy proso millets. During the cooking process, starch granules in the grains were gradually gelatinized starting from the outer region to the inner region and were gelatinized earlier in waxy proso millet than in non-waxy proso millet. Many filamentous network structures were observed in the cross sections of cooked waxy proso millet. As the cooking time increased, the long- and short-range, ordered structures of proso millets were gradually disrupted, and the ordered structures were fully disrupted by 20 min of cooking. In both waxy and non-waxy proso millets, thermal and pasting properties significantly changed with an increase in the cooking time. This study provides useful information for the processing of proso millet in the food industry.

Highlights

The grains of proso millet (Panicum miliaceum L.) have higher levels of proteins, several minerals, vitamins, and antioxidants than most other cereals [1]
As the cooking time increased, the gelatinization temperatures of proso millet flours significantly increased, while the ΔH of proso millet flours significantly decreased, which is in agreement with previous studies [11,27]
When the cooking time increased, the melting of starch crystallites and the formation of amylose–lipid complexes resulted in a decrease in enthalpy [37]

Summary

Introduction

The grains of proso millet (Panicum miliaceum L.) have higher levels of proteins, several minerals, vitamins, and antioxidants than most other cereals [1]. The cooking quality of proso millet, a key property of concern to consumers, plays an important role in the production, processing, and application of this grain, and relevant studies regarding this are scarce. Cereals such as rice and millet are principally consumed as cooked grains [3,8]. He et al [11]

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