Study On The Effect And Mechanism Of Lactic Acid Bacteria On The Mitigation Of Acrylamide In Vitro Digestion

Acrylamide is a highly reactive food source hazard,which is widely present in hot-processed foods.Studies have demonstrated its toxicity in neurons and reproduction,as well as its potential carcinogenicity and teratogenicity.To suppress acrylamide production,physical and chemical methods were commonly utilized.However,residual acrylamide in most food system affects food color,sensory quality and safety.Microorganisms such as Aspergillus oryzae,beer yeast,etc.have been reported to reduce acrylamide production,but the application of lactic acid bacteria in mitigating acrylamide and its mechanism have been rarely reported.The current study aims to control the production of free acrylamide in both food system and digestion process,and further reveal the effect and mechanism of Lactobacillus on acrylamide mitigation.1.Five strains characterized with high acrylamide-eliminating ability were selected from 12 Lactobacillus strains under simulated system.The acrylamide-alleviating capacity of five strains from high to low is Lactobacillus plantarum(Vege-Start 2.0CN),Lactobacillus plantarum(Vege-Start 60),Streptococcus thermophiles(ST-Body-3),Lactobacillus paracasei(L.casei 01)and Lactobacillus rhamnosus(Fresh Q2).The mitigation rate of Vege-Start 2.0CN-acrylamide under twelve hours' co-incubation was 54.66±0.50%.Physical adsorption plays a predominant role in the efficient acrylamide mitigation,which was demonstrated via nonviable and viable strains-binding experiment.The results also showed that adsorption rate of Lactobacillus in acrylamide increased with the increasing of bacteria concentration,co-cultivating time and pH value.Lactobacillus plantarum(Vege-Start 2.0CN)was observed to show the highest adsorption rate(88%)to acrylamide at pH=3.2.The acrylamide adsorption effect of different cell walls' compositions from Lactobacillus was compared through the analysis of cell wall structure and compositions of strains,suggesting the predominant role of peptidoglycan.When the concentration of peptidoglycan was 20 mg/mL,the binding rates ranged from 36.74%to 75.84%.It was found that total amount of sugar and amino acid were closely associated with the binding effect of Lactobacillus to acrylamide.Functional groups including C-O(carboxyl,polysaccharide,arene),C=O(amide bond I)and N-H(amine)participated in the adsorption reaction.3.The mitigation rates for acrylamide in brown milk by five selected strains ranged from 45.85%to 87.53%,with the highest adsorption rate of 87.53%for Lactobacillus plantarum(Vege-Start 2.0CN).The dynamic changes of acrylamide mitigation rates under working solutions of strains-acrylamide and strains-fried doughtwist were investigated in vitro simulated digestion.The results showed that the mitigation rates of acrylamide was 24.64±0.22?32.35±0.51%in strains-acrylamide working solution,and 10.93±0.25-40.06±1.15%in strains-fried dough twist,which can reduce the amount of acrylamide absorbed by human body and protect body from its toxic effects.