Lipid oxidation of brown rice stored at different temperatures

Abstract

Summary Changes in lipid oxidation and quality of brown rice stored at different temperatures were investigated. Fatty acid value (FAV), peroxide value (POV) and carbonyl value (CV) of brown rice were determined every 45 day for 270 day. Volatile compounds in seven samples stored for 0, 135 and 270 day were also identified. Relationships between volatile compounds and oxidative indices were analysed. Results revealed that the FAV, POV and CV of brown rice significantly increased (P < 0.05) with prolonged storage. Samples stored at low temperatures showed lower FAV, POV and CV than those stored at high temperatures. Brown rice stored under different conditions produced similar volatiles. Based on the principal component analysis of the volatiles, the first two principal components explained 58.20% of the variance. Volatiles of PC1 were correlated with FAV, POV and CV and can be used as an index to assess the quality of stored brown rice.

Impact of Postharvest Operations on Rice Grain Quality: A Review

“…Liu, Li, et al. () observed considerable losses for Mg, Mn, Fe, and Pb during milling (DOM = 9%; Table ). These results indicated that the variation in the loss of elements were both associated with the DOM and rice genotypes.…”

“…Liu, Li, et al. () showed that the content of crude lipid decreased from 2.43 to 2.86 g/100g to 0.60 to 0.60 g/100 mg with increased DOM from 0 to 15% (Table ). Monks et al.…”

“…The milling or polishing also had significant effects on nutritional aspects of milled rice since most of the minerals are concentrated in the aleurone layers. Numerous studies have suggested a considerable loss for rice grain macro‐ and micro‐elements, especially Zn and Fe (Liang et al., ; Liu et al., b; Prom‐u‐thai et al., ). Liang et al.…”

“…DOM also has large negative effects on ash contents in milled rice since ash reflects the mineral content of the bran layers of rice caryopsis (Heinemann, Fagundes, Pinto, Penteado, & Lanfer‐Marquez, ; Liu, Li, et al., ; Singh, Singh, Kaur, & Singh Bakshi, ). Liu, Li, et al.…”

Volatile compounds profile of Brazilian aromatic brown rice genotypes and its cooking quality characteristics

“…Bryant and McClung () evaluated the volatile profile of nine rice cultivars and eight of them exhibited hexanal prior to storage, demonstrating that lipid breakdown products can be quickly produced after harvest and that this is a cultivar‐dependent phenomenon. Liu, Li, Chen, and Yong () showed that when rice is stored at 15ºC, there is a delay of the oxidative rancidity of rice during long‐term storage, compared to 25 and 35ºC, but the type of synthesized volatiles is similar.…”