可可豆罐装发酵过程中挥发性成分变化规律研究

Study on Variation of Volatile Components in Bottled Cocoa Beans during Fermentation Process

以BGL46-35可可为试验材料进行控温罐装发酵法,利用顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME/GC-MS)对可可豆发酵过程中挥发性成分进行检测分析,揭示发酵过程中挥发性成分变化规律,为可可豆发酵机理提供理论基础。结果表明:在50℃恒温条件下,可可豆发酵7d过程中共检测出37种挥发性成分,由醇类、醛类、酮类、酸类、酯类、内酯类、烯烃类、吡喃类、呋喃类、醚类、亚砜类组成。在发酵过程中,挥发性成分数量整体呈现上升趋势;其中,醇类和酸类的数量和含量占比最多,含量呈整体下降的变化趋势。PCA分析表明,BGL46-35可可发酵过程中特征挥发性物质种类为醇类和酮类,未发酵豆的特征挥发性物质以(S)-2-戊醇为主,发酵完成的可可豆特征挥发性物质主要以乙酸、异戊醇、2-庚醇、2,3-丁二醇为主;相关性分析表明,发酵时间与烯烃类呈极显著正相关关系(P<0.01),吡喃类和呋喃类呈显著正相关关系(P<0.05),醇类与酸类呈极显著负相关(P<0.001)。

In order to reveal the variation of volatile components during the fermentation process of cocoa beans and provide a theoretical basis for the fermentation mechanism of cocoa beans,BGL46-35 cocoa beans was used as the experimental material to detect and analyze the volatile components during the fermentation process of cocoa beans by the temperature controlled canister fermentation method and gas chromatography-mass spectrometry(HS-SPME-GC/MS).The results showed that 37 volatile components were detected during the 7-day fermentation process of cocoa beans at the constant temperature of 50°C, which were alcohols, aldehydes, ketones, acids, esters, lactones, hydrocarbons, pyrans,furans, ethers and sulfoxides. During the fermentation process, the number of volatile components showed an overall increasing trend. Among them, alcohols and acids accounted for the largest proportion in terms of the quantity and content, and the content showed an overall decreasing trend. Principal Component Analysis (PCA) suggested that the characteristic volatile substances in the fermentation process of BGL46-35 cocoa beans were alcohols and ketones;the primary characteristic volatile substance of unfermented cocoa beans was (S)-2-pentanol;the main characteristic volatile substances of the fermentated cocoa beans were acetic acid, isoamyl alcohol, 2-heptanol, 2,3-butanediol. Correlation analysis showed that fermentation time had a significant positive correlation with hydrocarbons (P<0.01);it had a significant positive correlation with pyrans and furans (P<0.05);it had a significant negative correlation with alcohols and acids (P<0.001).