可可豆含有豐富的黃烷醇對人身體心臟血管健康具有極大的助益。本研究原料可可豆經7天木箱自然發酵，一半採用旋轉式乾燥機熱風50 ℃乾燥，另一半採用天然日曬乾燥直到可可豆水分含量降至約6%。以正相HPLC方法分析檢測黃烷醇單體到10聚體的含量，結果顯示前者熱風50 ℃乾燥可可豆之黃烷醇含量，為55.91±2.82 mg/g，而日曬乾燥可可豆之黃烷醇含量，為49.27±2.49 mg/g。接下來，探討可可果實不經發酵而直接乾燥(包括殺菁，熱風乾燥與日曬乾燥)後可可豆之保健指標成分黃烷醇之變化情形，發現可可黃烷醇之含量，以殺菁後乾燥最高達68.94±2.37 mg/g，熱風乾燥次之為51.11±1.77 mg/g，日曬乾燥最低為32.53±1.10 mg/g。但當製成巧克力產品時，未經發酵直接乾燥的可可豆缺乏巧克力的風味，無法被消費者接受。本研究同時分析市售國外可可豆黃烷醇單體到10聚體的含量，其含量範圍在34.06±1.21 mg到47.33±1.70 mg/g之間。結果顯示台灣自然落菌發酵經熱風乾燥可可豆的黃烷醇含量顯著的高於國外可可豆(p<0.05)。為了探討台灣可可豆在不同烘烤溫度和時間作用下，黃烷醇含量的變化情形，烘烤溫度分別是110，130和150 ℃，烘烤時間分別是15，25和35min。結果顯示黃烷醇含量隨著烘烤溫度與時間的增加而減少。從最高55.30±1.95mg/g(低溫110℃和15min）緩降至19.12±0.66mg/g（高溫150℃和35min)。黃烷醇變化的動力學研究顯示烘烤過程中其含量的變化遵守一級反應，反應速率與溫度的關係遵循阿瑞尼爾士方程式（Arrhenius equation)。得到的參數k0(頻率因子)其值為19930min-1與反應活化能Ea為11.2 kcal/mol。根據此方程式可以有效地預測在一般商業化巧克力烘烤製程下，可可豆中黃烷醇的含量。同時將上述9種不同烘烤溫度和時間作用下之可可豆製作成9種70%黑巧克力，並進行消費者型的品評分析，結果顯示130℃25min這組合接受度最高。對於開發具保健功效的巧克力產品提供有用的資訊。本研究亦探討不同發酵方式對台灣產可可豆的品質風味與特定保健指標成分的影響。發酵方式採用傳統的木箱固態發酵(菌株將分別採用自然落菌，強制添加酵母菌、強制添加乳酸菌及強制添加醋酸菌)，結果顯示針對強制添加不同菌種的發酵可可豆其黃烷醇的含量以強制添加乳酸菌之發酵可可豆最低為43.17±1.73mg/g，以自然落菌之發酵可可豆最高為44.38±1.74mg/g，並沒有顯著差異(p>0.05)，利用電子鼻進行氣味分析同時利用主成份分析發現不同菌種發酵的可可豆之風味有明顯不同。 Cacao beans are rich in polyphenols and flavanols that have numerous positive health benefits especially related to cardiovascular. In this study, the cacao pods were purchased from local farmer at Ping-Tung county in Taiwan. The cacao seeds were fermented in a wooden box for 7 days. Half the fermented beans by oven dried at 50℃ and the other by sun dried for 7 days until the moisture content of cocoa beans reached 6-7%. The content of cocoa flavanol and procyanidin(FP) (Degree of Polymerization 1-10) were determined by normal phase HPLC. The results showed that the levels of FP in oven dried beans and sun dried beans were 55.91±2.82 mg/g and 49.27±2.49 mg/g, respectively. The effects of different drying methods on the content of FP of Taiwan unfermented cocoa beans were conducted. The results indicated that the beans by blanching drying has the highest content of FP(68.94±2.37 mg/g) and the beans by direct sun dried has the lowest level of FP(32.53±1.10 mg/g). This study also compared the FP content of Taiwan bean with the different country origins. It showed that the FP( content of Taiwan bean by oven dried is significantly higher than the other countries in the range of 34.06±1.21 mg/g and 47.33±1.70 mg/g at p<0.05. This study also investigated the influence of the roasting conditions of cocoa beans at different roasting temperatures (110, 130 and 150℃) and roasting time ( 15, 25 and 35min) on the cocoa bean flavor and quality. The results showed the FP content decreased with the increase of roasting temperature and time, from the highest 55.30±1.95mg/g at 110℃ and 15min slowly declined to the lowest 19.12±0.66mg/g at 150℃ and 35min. The kinetic study showed that the FP change in cocoa bean is according to the first order reaction and the reaction rate constant complied with the Arrhenius equation. The value of frequency factor (k0 ) is equal to 19930 min-1 and the activation energy (Ea) is equal to 11.2 kcal/mol. The sensory evaluation for the above 9 chocolate products indicated the bean baking at 130℃ and 25min with the highest acceptability by 44 panels. In addition, this study also investigated the effects of inoculated different microorganism strains ( the strains includes natural occurring yeast, Acetobactor aceti, Saccharomyces cerevisiae, and Lactobacillus plantarum, respectively) on the cocoa bean flavor and quality. The results showed that the bean fermented by natural occurring microorganisms has the highest levels of FP (44.38±1.74mg/g) and the bean fermented by inoculated Lactobacillus plantarum has the lowest levels of FP(43.17±1.73mg/g), but they are not significantly different (p>0.05). In addition, according to the flavor analysis by electronic nose and primary component analysis, It showed that there exists a big difference among these cocoa beans fermented by different strains.
