Study On The Effect Of Sourdough Fermentation Combined With Microwave Heating On The Level Of FODMAPs In Sponge Cakes

Fermentable oligo-,di-,and monosaccharides,and polyols(FODMAPs),is a type of shortchain carbohydrates that are not easily absorbed by the small intestine.Excessive intake of FODMAPs may cause the deterioration of irritable bowel syndrome(IBS).Low FODMAPs diet has been previously shown to effectively relieve symptoms of IBS patients.The main FODMAPs in wheat-based food are fructans,which can be hydrolyzed by fructanase.It has been proven that sourdough can effectively reduce the content of FODMAPs in bread,and thermal processing has a positive effect on reducing its content.Therefore,this study aimed to evaluate lactic acid bacteria(LAB)during sourdough fermentation,and using microwave method to assist in enhancing the degradation of fructan.The aim is to develop traditional fermented wheat-based food with high quality and low FODMAPs,and to clarify the degradation mechanism of FODMAPs by LAB fermentation and microwave processing.The main research contents and results are as follows:1)Screening of LAB with the function of degrading FODMAPsBased on the phylogenetic analysis of fructanase in lactic acid bacteria,there were screened out 11 strains of Lactobacillus paracasei with extracellular ?-fructosidase Fos E.L.paracasei FJSSZ3L1 was selected to effectively degrade fructans by sourdough fermentation.?-Fructosidase Fos E mainly exists on the cell wall,and a few are secreted outside the cell.And it has selective specificity for hydrolyzing substrates,preferentially hydrolyzing ?-(2,1)-bonded fructans.2)Effect of LAB fermentation on the content of FODMAPs in sourdough and sponge cakeThe effect of fermentation of L.paracasei FJSSZ3L1 on the content of FODMAPs in sourdough and sponge cake was investigated.The results show that extending the fermentation time is beneficial to reduce the content of FODMAPs in the product;?-fructosidase Fos E has exohydrolysis activity and preferentially hydrolyzes fructans with a higher degree of polymerization.The sourdough sponge cake fermented by L.paracasei FJSSZ3L1 meets the requirements of IBS patients for a low FODMAPs diet3)The effect of microwave heating on the content of FODMAPs in sponge cakeCompared with traditional steaming,microwave heating can effectively help degrade fructans in sponge cakes.In addition,the microwave power and heating time have a significant correlation with the content of FODMAPs,and the degradation effect of Saccharomyces cerevisiae products is more significant.The degradation mechanism of fructans under different heating methods was explored,and the results showed that the rapid heating effect of microwave was not significantly related to the degradation of fructans,and microwave heating could increase the activity of fructan degrading enzymes,thereby promoting the hydrolysis of fructans.4)The effect of sourdough fermentation on the quality characteristics of low-FODMAPs sponge cake heated by microwaveIn order to explore the effects of microwave heating and the degradation of FODMAPs on the quality characteristics of sponge cakes,the effects of microwave heating with different starters on the water loss,specific volume and total texture(TPA)characteristics of sponge cakes were studied and compared.The results showed that excessive microwave heating and the reduction of fructan content caused product quality deterioration.However,the addition of sourdough played a positive role in improving the quality characteristics of microwave-heated sponge cakes.