The Effects of Thermal Treatment on Lipid Oxidation, Protein Changes, and Storage Stabilization of Rice Bran

Abstract

Rice bran is a nutrient-rich and resource-dense byproduct of rice milling. The primary cause of rice bran utilization limitation is oxidative deterioration and inadequate storage facilities. Improving stability to extend the shelf-life of rice bran has thus become an utmost necessity. This study aimed to stabilize raw fresh rice bran (RB) by using dry heat methods at 120 °C (233, 143, and 88 min) and 130 °C (86, 66, and 50 min). The results indicated that after dry heat pretreatment, peroxidase levels were at 90%, and the storage stability of dry-heat-stabilized RB was better. However, with an increase in treatment temperature and time, the peroxidase activity improved while the lipase activity decreased to a certain extent without significant changes. The total saturated and unsaturated fatty acids were significantly unchanged during storage, while oleic/linoleic acid increased substantially by 1% at 120 °C for 88 min. The increase in treatment time and temperature was beneficial in controlling the fatty acid values. However, extended treatment time caused an increase in the peroxide value and MDA. The essential and non-essential amino acid ratios, which evaluate a protein’s nutritional value, remained relatively stable. The essential subunit of rice bran protein was not affected by the temperature and time of dry heat treatment and storage time.

Effects of full fat oil seeds on milking performance, milk composition and milk quality in lactating Holstein cows

“…Unsaturated fatty acids in foods can readily bind oxygen due to their double bond structure (Chan, 1987), and the auto-oxidation of foods has been found to increases with the content of free fatty acids and degree of unsaturation (You and Lee, 1982). In addition, oxidative changes are carried out by lipolytic enzymes, hydrolysis, and microorganisms, and the longer the storage period and the higher the temperature, the faster the rate of lipid oxidation (Rashid et al, 2022). In the present study, lipid oxidation rapidly progressed under storage at 15 °C, which was consistent with previous research results.…”

Nutritional composition and volatile compounds stability in dry‐heat and extruded stabilised rice bran during storage

“…Fresh samples were placed on an open shallow pan and evenly spread on a thin layer. The pans were then put in a laboratory oven using two different temperatures with different time durations, such as at 120 °C for 233, 143, and 88 min, and at 130 °C for 86, 66, and 50 min (Rashid et al ., 2022). Whereas untreated rice bran was stored as the control group.…”

“…It is feasible to use extrusion cooking and dry heat treatment to stabilise rice bran, which has commercial potential, so the two stabilisation methods are compared. In connection with our previous studies, Rashid et al (2022) where we have discussed in detail the lipid oxidation, protein changes, fatty acid profile and so on, here in the current study we tried to focus on some other important aspects like phytochemicals, dietary fibre, c-oryzanol content, volatile compounds and quality related nutritional attributes of stabilised RB to further elaborate the efficiency of applied stabilisation treatments on RB.…”

Unlocking the potential of rice bran through extrusion: a systematic review

“…Protein can be denatured in extrusion due to high temperature and shear force, but many studies suggest no signicant effect on the protein content of RB. 61 Extrusion-induced hydrolysis of phytates in RB contributes to increased mineral availability, such as copper and zinc. 62 In the extrusion of RB, SDF was 51.49% as compared to unprocessed SDF.…”