Impact of environmental factors on rice starch structure: A review

Abstract

Among cereal grains, rice is the world's leading source of caloric energy in the human diet. About 90% of a milled rice kernel is starch (dry weight basis), thus justifying the need to understand the impacts of factors affecting starch composition and behavior when processed. This review presents past and current perspectives regarding the effects of growing environment on the macro, micro, and nano level structures of rice starch. The environmental elements considered in this work are: air temperature, atmospheric carbon dioxide, light, water, and soil nutrients. All these elements are essential for plant development and reproduction. The effect of air temperature is the most widely explored aspect of the environment in relation to rice production and grain quality. This could be attributed in part to the recently purported and highly publicized global warming phenomenon. Amylose content has remained a major predictor of rice starch quality but emerging instrumental techniques have facilitated more thorough research addressing the fine structure of amylopectin, which constitutes ∼70% of the starch present in a milled rice kernel. Kernel chalkiness appears to be the most common visual manifestation of environment‐related stress. Typically, there are genotype by environment interactions; this may result in inconsistent temporal and spatial findings. However, such interactions may prove useful in identifying particular genotypes that are adaptable and stable across growing locations.

Physicochemical properties, modifications and applications of starches from different botanical sources

“…Wild type Angular, polygonal (Hoover et al, 1996) < 20 (Singh et al, 2003) 2-8 (Hoover et al, 1996;Patindol et al, 2015) 0.6-1.4 (Dhital et al, 2011) 0.1 (Hoover et al, 1996) 0.1 (Lim et al, 1994) 21-25 (Patindol et al, 2015) Waxy 0-2 (Patindol et al, 2015) High amylose > 25 (Patindol et al, 2015) Corn Wild type Angular (Singh et al, 2003) 11.5± 0.3 (López et al, 2010) 0.6-0.8 (Dhital et al, 2011) 0.3-0.53 (Morrison et al, 1984) 0.4 (Dhital et al, 2011) 0.31-0.35 (Sang et al, 2007) 28. 5 Nuwamanya et al, 2013) 23.86 ± 0.66 (López et al, 2010) 25.8-32.5 (Morrison et al, 1984) 19.2 ±1.4/A (López et al, 2010) Waxy 0.01-0.05 (Morrison et al, 1984) 1.4-2.7 (Morrison et al, 1984) High amylose Polygonal and Angular (Ellis et al, 1998) 0.38-0.67 (Morrison et al, 1984) 0.02 (Lim et al, 1994) 70 (Lim et al, 1994) 42.6-67.8 (Morrison et al, 1984) Lipid, protein and phosphorus contents are shown as % of total dry weight.…”

Amylose content and RVA profile characteristics of noodle rice under different conditions

“…A quadratic curve relationship exists between the amylose content and the temperature during the grain‐filling stage in most varieties and the temperature during the early grain‐filling period has the largest impact (Ahmed et al., ; Zhou, Zhang, Gao, & Zhu, ). Likewise, the amylose content of Indica cultivars was parabolically correlated to the temperature for 20 d after full heading under artificial temperature control (Patindol, Siebenmorgen, & Wang, ), although the amylose content was found to be negatively correlated with sunshine hours during the grain‐filling period (Yun et al., ).…”

Grain Amylose Content and its Stability over Seasons in a Selected Set of Rice Varieties Grown in Sri Lanka

“…The environmental conditions such as the temperature and day length and genotype × environment interaction also affect the amylose content of different varieties of rice (Lin et al, 2005). Several other studies have shown that the interaction between genotype and ambient temperature also has an effect on amylose content in rice grains (Nkori Kibanda and Luzi-kihupi, 2007;Patindol et al, 2015). Thus, amylose content varies over seasons in the same site of cultivation even with the same variety (Inatsu, 1979;Asaoka et al, 1984).…”