Nionelli Luana, Pontonio Erica, Gobbetti Marco, Rizzello Carlo Giuseppe
Department of Soil, Plant and Food Science, University of Bari Aldo Moro, 70126 Bari, Italy.
Facoltà di Scienze e Tecnologie, Free University of Bozen-Bolzano, 39100 Bolzano, Italy.
Int J Food Microbiol. 2018 Feb 2;266:173-182. doi: 10.1016/j.ijfoodmicro.2017.12.002. Epub 2017 Dec 5.
Aiming at meeting the consumers' demand in terms of bio-preservation, the potential of the combination of the lactic acid bacteria fermentation and the addition of hop extract as natural preservative in breadmaking, was exploited. The antifungal properties of a hop (Humulus lupulus) extract were investigated, showing a significant inhibition of the hyphal growth of Aspergillus parasiticus, Penicillium carneum, Penicillium polonicum, Penicillium paneum, Penicillium chermesinum, Aspergillus niger, Penicillium roqueforti. Lactic acid bacteria belonging to species of Enterococcus feacium, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus helveticus, Lactobacillus curvatus, Pediococcus pentosaceus, and Pediococcus acidilactici were isolated from hop and subjected to selection based on kinetics of growth and acidification. The sourdough (hS) enriched with hop extract (hE), started with three selected strains, had phenols concentration and antioxidant activity higher than those obtained in the same condition but without the hE. Hop-sourdough used in breadmaking delayed the fungal growth (14 days), giving a bread characterized by free aminoacids concentration, antioxidant and phytase activities higher than bread started only with baker's yeast, with or without the addition of hE. Specific volume and cell-total area of the bread containing hE improved, and its sensory profile was characterized by typical sourdough attributes, and a moderate bitter/herbaceous perception.
为了满足消费者对生物保鲜的需求,研究了乳酸菌发酵与添加啤酒花提取物作为天然防腐剂在面包制作中的潜在应用。对啤酒花(Humulus lupulus)提取物的抗真菌特性进行了研究,结果表明其对寄生曲霉、肉色青霉、波兰青霉、潘氏青霉、红褐青霉、黑曲霉、罗克福特青霉的菌丝生长有显著抑制作用。从啤酒花中分离出属于粪肠球菌、植物乳杆菌、短乳杆菌、瑞士乳杆菌、弯曲乳杆菌、戊糖片球菌和嗜酸片球菌的乳酸菌,并根据生长和酸化动力学进行筛选。用三种选定菌株制作的富含啤酒花提取物(hE)的酸面团(hS),其酚类物质浓度和抗氧化活性高于相同条件下未添加hE的酸面团。用于面包制作的啤酒花酸面团延缓了真菌生长(14天),所制得面包的游离氨基酸浓度、抗氧化和植酸酶活性高于仅用面包酵母制作的面包,无论是否添加hE。添加hE的面包的比容和细胞总面积有所改善,其感官特征具有典型的酸面团特性以及适度的苦味/草本味。