Kaprasob Ratchadaporn, Kerdchoechuen Orapin, Laohakunjit Natta, Thumthanaruk Benjawan, Shetty Kalidas
1School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, 49 Teintalay 25 Rd., Thakam, Bangkhuntein, Bangkok, 10150 Thailand.
2Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, 1518 Pracharat 1 Rd., Wongsawang, Bangsue, Bangkok, 10800 Thailand.
J Food Sci Technol. 2018 Oct;55(10):3979-3990. doi: 10.1007/s13197-018-3323-7. Epub 2018 Jul 7.
Changes in physico-chemical qualities (pH, total acidity, total and reducing sugar, total phenolic and vitamin C), astringency compounds (condensed and hydrolysable tannin), antioxidant activities [2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical] and flavor volatile compounds in -fermented cashew-apple-juice (CAJ) and 11.4 °Bx concentrated-cashew-apple-juice (CCAJ) was investigated. Total phenolics remained unchanged throughout fermentation period, whereas condensed tannins increased and hydrolysable tannins decreased indicating reduced astringency compounds. Antioxidant activity based on both DPPH and ABTS radical scavenging activities marginally declined in some stages but overall were sustained during fermentation. Although the DPPH radical based antioxidant activity of fermented CAJ was greater than that of fermented 11.4 °Bx CCAJ, a higher ABTS radical scavenging activity was found in fermented 11.4 °Bx CCAJ, reflecting higher water soluble antioxidants. Results also indicated that DPPH radical scavenging activity was positively correlated to vitamin-C and condensed tannins but not hydrolysable tannins. ABTS radical scavenging activity was also positively correlated to condensed tannins and not hydrolysable tannins. The vitamin-C that increased during initial 12 h fermentation, decreased from 2516 to 2150 mg AAE/L at the end of 72 h fermentation. Fermented CAJ had a remarkable sweet aroma with a fruity note of two major compounds; 3-methyl-1-butanol (14.20 × 10) and 2,6-dimethyl-4-heptanol (14.76 × 10). The high phytochemicals and volatile compounds in fermented CAJ indicated that it could serve as a functional beverage with potential health benefits with reduced astringency due to lower hydrolysable tannins.
研究了发酵腰果苹果汁（CAJ）和11.4°Bx浓缩腰果苹果汁（CCAJ）的理化性质（pH值、总酸度、总糖和还原糖、总酚和维生素C）、涩味化合物（缩合单宁和水解单宁）、抗氧化活性[2,2-二苯基-1-苦基肼（DPPH）和2,2'-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS）自由基]以及风味挥发性化合物的变化。在整个发酵过程中，总酚含量保持不变，而缩合单宁增加，水解单宁减少，表明涩味化合物减少。基于DPPH和ABTS自由基清除活性的抗氧化活性在某些阶段略有下降，但在发酵过程中总体保持稳定。尽管发酵CAJ基于DPPH自由基的抗氧化活性高于发酵11.4°Bx CCAJ，但在发酵11.4°Bx CCAJ中发现了更高的ABTS自由基清除活性，反映出更高的水溶性抗氧化剂。结果还表明，DPPH自由基清除活性与维生素C和缩合单宁呈正相关，与水解单宁无关。ABTS自由基清除活性也与缩合单宁呈正相关，与水解单宁无关。在最初12小时发酵期间增加的维生素C，在72小时发酵结束时从2516毫克AAE/L降至2150毫克AAE/L。发酵CAJ具有浓郁的甜香，带有两种主要化合物的果香；3-甲基-1-丁醇（14.20×10）和2,6-二甲基-4-庚醇（14.76×10）。发酵CAJ中高含量的植物化学物质和挥发性化合物表明，它可以作为一种功能性饮料，由于水解单宁含量较低，具有潜在的健康益处且涩味降低。
