不同乳酸菌发酵对菠萝浆品质的影响

Effect of different lactic acid bacteria fermentation on the quality of pineapple pulp

以菠萝浆为原料,添加干酪乳杆菌、植物乳杆菌和肠膜状明串珠菌单一或复配发酵,测定发酵24 h后的蛋白酶酶活、超氧化物歧化酶(SOD)酶活、总酚含量、DPPH自由基清除能力、挥发性物质及冻干成粉后的维生素C含量。结果表明,乳酸菌单一发酵效果整体上要好于复配发酵,干酪乳杆菌单独发酵可使菠萝浆的SOD酶活保持在97.70 U/g,总酚含量达到最高(0.51 mg没食子酸当量(GAE)/g);植物乳杆菌单独发酵菠萝浆时蛋白酶活性最好(821.00 U/mL),同时DPPH自由基清除能力最高,达到5.37μmol Trolox当量(TE)/g;肠膜状明串珠菌单独发酵组的维生素C含量最高,为4.73 mg/g;菠萝浆经干酪乳酸菌和植物乳杆菌单独发酵后,鉴定出的挥发性成分分别达到29和28种。综上,选择干酪乳杆菌或植物乳杆菌单独发酵菠萝浆能获得较好的品质。

Using pineapple pulp as raw material, Lactobacillus casei, Lactobacillus plantarum and Leuconostoc mesenteroides were inoculated for single or compound fermentation, and the activity of protease, superoxide dismutase(SOD), total phenol content, DPPH free radical scavenging ability, volatile matter and vitamin C content after freeze-dried were determined after fermentation 24 h. The results showed that the single fermentation effect of lactic acid bacteria was better than that of the compound fermentation. The SOD activity of pineapple pulp fermented by L. casei could keep at 97.70 U/g, and the total phenol content reached the highest(0.51 mg gallic acid equivalent(GAE)/g). The protease activity and DPPH free radical scavenging ability of pineapple pulp fermented by L. plantarum were the highest, which were 821.00 U/ml and 5.37 mol Trolox equivalent(TE)/g, respectively. The content of vitamin C in pineapple pulp fermented by L. mesenteroides was the highest, which was 4.73 mg/g. After the pineapple pulp was fermented by L. casei and L. plantarum, a total of 29 and 28 volatile components were identified, respectively. In conclusion, choosing L. casei or L. plantarum to ferment pineapple pulp alone could obtain better quality.