乳酸菌发酵饼干的品质特性

Quality Characteristics of Lactic Acid Bacteria Fermented Crackers

摘要:

为研究乳酸菌发酵对饼干的蛋白质消化性和品质特性的影响，分别采用两种乳酸菌（植物乳杆菌DN-1、副干酪乳杆菌JN-1）与酵母共同发酵制备饼干，测定饼干的蛋白质体外消化率、蛋白质营养指标、品质和风味的变化。研究结果表明，与酵母单独发酵饼干（Control饼干）和市售梳打饼干相比，两种乳酸菌发酵饼干在胃肠消化阶段的蛋白质体外消化率均有所提高，其中在肠消化阶段DN-1饼干的蛋白质体外消化率最高，与酵母单独发酵饼干相比，其蛋白质体外消化率从81%提高至86%；同时，两种乳酸菌发酵饼干的硬度和脆性均有所降低；根据固相微萃取-气相色谱-质谱联用的测定结果可知，乳酸菌发酵饼干中酯类和醇类总相对含量和种类有明显的提高，与酵母单独发酵饼干相比，DN-1发酵饼干中酯类和醇类相对含量占比分别提高了335%、30%，其酯类物质和醇类物质的种类分别为26、24种。综上，乳酸菌发酵能提高饼干产品的蛋白质体外消化率，改善并丰富产品风味。

Abstract:

To investigate the effects of fermentation with lactic acid bacteria on the protein digestibility and quality characteristics of crackers, two types of lactic acid bacteria (Lactobacillus plantarum DN-1, Lactobacillus plantarum JN-1) were used in combination with yeast for fermentation to prepare biscuit products, respectively. The in vitro digestibility and nutritional indexes of protein and changes in quality and flavor of fermented crackers were determined. The results showed that compared with yeast-only fermented crackers and commercial soda biscuits, the in vitro digestibility of protein in crackers fermented with two types of lactic acid bacteria was both increased during the gastrointestinal digestion stage, with the highest in vitro digestibility of protein observed in crackers fermented with DN-1. The in vitro digestibility of protein increased from 81% to 86% compared with yeast-only fermented crackers during the intestinal digestion stage. Meanwhile, the hardness and crispness of cracker fermented with two types of lactic acid bacteria were both reduced. The results of solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) showed a significant increase in the total and species of esters and alcohols in crackers fermented with lactic acid bacteria. Compared with yeast-only fermented crackers, the relative content of esters and alcohols in DN-1-fermented crackers increased by 335% and 30%, respectively, with 26 and 24 species of esters and alcohols detected. Overall, fermentation with lactic acid bacteria can enhance the in vitro digestibility of protein in crackers, and improve and enrich the flavors of products.