Research Unit VEG-i-TEC, Department of Food Technology, Safety and Health, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium; Department of Food Biotechnology and Nutritional Sciences, Nelson Mandela African Institution of Science and Technology, 447 Arusha, Tanzania.
Research Unit VEG-i-TEC, Department of Food Technology, Safety and Health, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium.
Food Chem. 2021 Oct 1;358:129809. doi: 10.1016/j.foodchem.2021.129809. Epub 2021 Apr 19.
Fermentation increases food shelf-life but is characterized by changes that affect product's perception. Watermelon juice was fermented with Lactobacillus plantarum (WJ-LP), L. rhamnosus (WJ-LR), L. casei (WJ-LC), L. brevis (WJ-LB) and Pediococcus pentosaceus (WJ-PP). Their sensory characteristics and volatile compounds were investigated by consumers and Headspace Solid Phase Microextraction integrated with Gas Chromatography-Mass Spectrometry, respectively. WJ-PP and WJ-LB were most liked and perceived with 'watermelon-flavor', 'natural taste', 'sweet' and 'watermelon-color' while WJ-LC, WJ-LP and WJ-LR were least liked and perceived as 'sour', 'bitter', 'off-flavor', 'aftertaste' and 'intense-flavor'. Fifty-four volatiles were identified. After fermentation, alcohols, ketones, monoterpenes, acids, and furans increased while aldehydes and alkanes decreased. Lactic acid fermentation introduced 4-decanone and 2,3-butanedione in WJ-LB, WJ-LC, WJ-LP and WJ-LR, however, heptanal, 2-heptenal, 2,6-nonadienal, 2-decenal, and 2,4-decadienal in WJ-LC, heptanal, 2-hexenal, 2-heptenal, 2,6-nonadienal, 2-decenal and octanal in WJ-LR and 2,6-dimethyl-2,6-octadiene in WJ-LP disappeared. Juice sensory profiles were associated with their volatile compounds.
发酵可以延长食品的保质期，但也会导致产品感官特性发生变化。本研究利用植物乳杆菌（WJ-LP）、鼠李糖乳杆菌（WJ-LR）、干酪乳杆菌（WJ-LC）、短乳杆菌（WJ-LB）和戊糖片球菌（WJ-PP）对西瓜汁进行发酵，利用消费者感官评价和顶空固相微萃取-气相色谱-质谱联用技术分别分析发酵前后西瓜汁的感官特性和挥发性风味物质。结果表明，WJ-PP 和 WJ-LB 最受消费者欢迎，被评价为具有“西瓜风味”“自然味道”“甜味”和“西瓜色”，而 WJ-LC、WJ-LP 和 WJ-LR 则被评价为“酸味”“苦味”“异味”“回味”和“强烈风味”。共鉴定出 54 种挥发性风味物质，发酵后西瓜汁中醇类、酮类、单萜类、酸类和呋喃类化合物的含量增加，醛类和烷烃类化合物的含量降低。LB、LC、LP 和 LR 发酵液中分别产生了 4-癸酮和 2,3-丁二酮，而 LC 发酵液中产生了庚醛、2-庚烯醛、2,6-壬二烯醛、2-癸烯醛和 2,4-癸二烯醛，LR 发酵液中产生了庚醛、2-己烯醛、2-庚烯醛、2,6-壬二烯醛、2-癸烯醛和辛醛，而 LP 发酵液中则产生了 2,6-二甲基-2,6-辛二烯。西瓜汁的感官轮廓与其挥发性风味化合物密切相关。
