Characteristics of peach wines made from different cultivars and evaluation on their suitability for wine brewing

Abstract: 【Objective】Peach (Prunus persica L.) is a nutritive fruit rich in carbohydrates, vitamins, minerals, organic acids, dietary fiber, and phenolic compounds. However, the peach is also a highly per- ishable fruit that is difficult to preserve owing to its physiological characteristics, leading to a short shelf life and serious postharvest losses. So it is necessary to develop peach processing products to alle- viate the postharvest losses. Among the various peach processing products, peach wine seems to be more promising and popular with consumers due to its delicate flavor and nutritive value. However, the information about the brewing of peach wine is limited, and little data about the effect of peach and nec- tarine cultivars on the wine quality and suitability for wine brewing could be found up to now. This re- search aims to characterize the quality of peach wines made from different cultivars and evaluate their suitability for wine brewing.【Methods】Fruits of 13 peach and nectarine cultivars, including 6 white- fleshed cultivars (Okubo, Zhong Pan Tao 10, Chun Mi, Hakuho, Kurakato Wase, Xia Cui), 3 yellow- fleshed cultivars (Shu Guang, Zhong Nong Jin Hui, NJC 83), and 4 red-fleshed cultivars (Wanzhou Su- an Tao, Zhong Tao Fei Yu, Wuhan 2, Da Hong Pao), were harvested at maturity, washed, pulped and then fermented at temperature of (20±1) °C with inoculation of Saccharomyces cerevisiae and addition of 60 mg·kg-1 of SO2. The wine was separated by filtering the pomace when the residual sugar remained   no change and stored at (20±1) °C for additional 30 d. After that time, the wine was centrifuged at 11 328×g for 15 min and the resulting supernatant was used for determination of sensory property, clari- ty, color, pH, and contents of titratable acidity, sugar-free extract, ethanol, methanol, higher alcohols, to- tal phenolics, flavonoids, anthocyanins as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scav- enging activity【. Results】There were great differences among the wines made from fruits of different peach and nectarine cultivars. The color of the wines differed according to the flesh color. The wines made from fruits of Wanzhou Suan Tao and Zhong Tao Fei Yu showed an appealing red color, while those of Zhong Nong Jin Hui and NJC 83 showed a desirable yellow color. However, the wines made from fruits of white-fleshed peach and nectarine cultivars showed a yellowish brown color due to the browning reaction during fermentation and storage. The pH, titratable acidity, sugar-free extract and al- coholic content of each peach wine was between 3.46- 4.02, 4.22- 6.79 g · L- 1, 20.60- 37.46 g · L- 1 and 9.43%-11.93%vol, respectively, which was generally satisfactory for fruit wine. The contents of total phenolics, flavonoids, anthocyanins, and DPPH radical scavenging activity for each peach winewere between 183.02-437.22 mg·L-1, 40.03-212.07 mg·L-1, 0-843.29 μg·L-1, and 237.51-661.61 μmol·L-1, respec- tively. Among the tested cultivars, the wine made from Wanzhou Suan Tao fruits showed the highest contents of total phenolics, flavonoids, anthocyanins, and DPPH radical scavenging activity, indicating that Wanzhou Suan Tao was a desirable cultivar for producing fruit wine with good health benefits. However, the wine made from Wanzhou Suan Tao fruits showed a higher methanol content due to the high pectin content in fruit, and the content of higher alcohols was also higher than most of other culti- vars. This indicated that some procedure should be performed to reduce the production of these com- pounds during fermentation and storage. The wine made from Zhong Tao Fei Yu fruits also showed higher contents of total phenolics, flavonoids, anthocyanins, and DPPH radical scavenging activity, while the contents of methanol and higher alcohols were much lower, so it might be another desirable red-fleshed cultivar for peach wine brewing. Hakuho, a white-fleshed peach cultivar, yielded relatively higher contents of total phenolics, flavonoids, anthocyanins, and the DPPH radical scavenging activity was second only to that of Wanzhou Suan Tao. Furthermore, the contents of methanol and higher alco- hols in Hakuho peach wine were relatively lower. Thus, Hakuho was suggested as the most suitable white-fleshed peach cultivar for producing fruit wine with good health benefits and safety. The wine made from Kurakato Wase fruits had the lowest contents of methanol and higher alcohols among the white-fleshed peach and nectarine cultivars, indicating a higher safety for drink. Despite the lower con- tent of phenolics and antioxidant capacity, the wines made from fruits of NJC 83 and Zhong Nong Jin Hui showed a desirable yellow color and typical flavor of peach, and the methanol content was relative- ly lower, suggesting that they were the promising cultivars for producing peach wine of yellow color.【Conclusion】The wines made from fruits of different fleshed color of peach and nectarine cultivars showed different quality characteristics. The red-fleshed cultivars of Wanzhou Suan Tao and Zhong Tao Fei Yu, white-fleshed cultivars of Hakuho and Kurakato Wase, yellow-fleshed cultivars of NJC 83 and Zhong Nong Jin Hui seemed to be more suitable for producing peach wines with different characteris- tics.