Mechanism of rice bran lipase inhibition through fermentation activity of probiotic bacteria

Abstract

Rice bran oil is known as wonder oil and it is the most important vegetable oil in Asia. Rice bran oil is extracted from bran that is the outer hard layer of rice. It is an emerging category in edible oil with a lot of nutritional properties and health benefits. Rice bran oil is heart-friendly, boosts up immunity, and prevents from other diseases occurring commonly in Pakistan. The current study aimed to stabilize rice bran oil through different probiotic isolates and to assess the nutritional content of rice bran oil after stabilization. The study was aimed to inactivate naturally occurring lipases that can hydrolyze oil into glycerol and free fatty acid which is a serious problem that gives it a rancid taste and smell. Antilipase activity was used to inactivate naturally occurring lipases that are a huge threat to the stabilization process. The fermentation process utilizes antilipase activity without affecting the nutritional value of oil. Lactobacillus strains were used for the stabilization of rice bran oil. Rice bran oil was extracted in the Soxhlet apparatus. The probiotic lab isolates Lactobacillus delbrueckii S2, Lactobacillus casei S5 and Lactobacillus plantarum S13 were applied to it to increase its shelf life and prevent oxidative rancidity. The extraction temperature of rice bran oil was maintained above 40 ° C to inhibit lipase activity. Rice bran oil samples were stored at refrigeration temperature to arrest lipase activity. Probiotics maintained acidic pH to keep oil stabilization. Qualitative analysis was done to confirm rice bran oil stabilization. Determination of Free Fatty Acid (FFA) and saponification value confirmed that oxidative rancidity of rice bran oil was controlled by probiotics. FFA count was less than 10% and Saponification Value (SV) was 180. GC analysis was performed to analyze the FFA profile. Gas Chromatography results have shown 3 fatty acids. Statistical analysis has shown non-significant effect on different incubation temperatures of Lactobacillus isolates. Among the biological methods of stabilization, the use of probiotics is a novel concept and recommended for commercial application.

Screening of Lactic Acid Bacteria Suitable for the Fermentation of Shenheling Slimming Beverages Based on the Activity Inhibition of Energy Digestive Enzymes and a Sensory Evaluation

“…Dealcoholized apple juice sequentially fermented with Saccharomyces cerevisiae and L. plantarum improved obesity and fatty livers in mice on a high-fat diet better than unfermented apple juice [35]. However, only Hong et al [36] studied the potential of yogurt fermented with safflower extract to inhibit pancreatic lipase in vitro; Noureen et al [37] studied the inhibitory effect of fermented rice bran on lipase activity. Our previous study also found that SHLE fermented with L. fermentum grx08 significantly enhanced the anti-obesity efficacy [28].…”

Developing Lipase Inhibitor as a Novel Approach to Address the Rice Bran Rancidity Issue─A Critical Review

“…51 Noureen et al have also reported that fermentation by Lactobacillus plantarum can stabilize rice bran by keeping an acidic pH value, which is not a suitable environment for rice bran lipase to catalyze the lipid (for the optimum pH value of rice bran lipase is 7.5−8.0). 23 Recently, Bolinedi et al reported that reducing the lipase or LOX expression, lowing the PUFA content (e.g., linoleic acid), or enhancing intrinsic antioxidants (e.g., γ-oryzanol) levels in rice bran through operating genome editing (e.g., CRISPR) on rice seeds is another promising approach in preventing rice bran rancidity. 17 These genetic and genome approaches are considered sustainable and costeffective; however, their development is still in its infancy.…”

“…Earlier, Vishwanath et al showed that lipase activity was completely inhibited, and the LOX activity was reduced by 50% after treatment with alcalase, but the viable nutrients and nutraceuticals were unaffected . Noureen et al have also reported that fermentation by Lactobacillus plantarum can stabilize rice bran by keeping an acidic pH value, which is not a suitable environment for rice bran lipase to catalyze the lipid (for the optimum pH value of rice bran lipase is 7.5–8.0) . Recently, Bolinedi et al reported that reducing the lipase or LOX expression, lowing the PUFA content (e.g., linoleic acid), or enhancing intrinsic antioxidants (e.g., γ-oryzanol) levels in rice bran through operating genome editing (e.g., CRISPR) on rice seeds is another promising approach in preventing rice bran rancidity .…”

“…Rice bran lipase is a dominant factor associated with the onset of lipid mobilization. So far, many efforts have been devoted to decreasing the activity of rice bran lipase to avoid the production of FFA, including acid treatment, ohmic heating, microwave heating, γ-irradiation, extrusion, enzyme hydrolyzing, and genetic modification. ,− For example, He et al reported that subjecting rice bran to infrared radiation at 300 °C for 210 s reduced its lipase activity by 73.05%, thereby reducing the content of FFA to 2.35% after storage at 4 °C for 8 weeks . A study by Thunnop et al found that treating rice bran with papain for 120 min suppressed its lipase activity by 79% and constrained its FFA content to 3.92% after two months of storage .…”