J Food Sci Nutr Res 2020; 3 (1): 001-017 DOI: 10.26502/jfsnr.2642-11000035 Journal of Food Science and Nutrition Research 1 Research Article Optimal Fermentation Conditions and Storage Period of Fermented Beverages Made from Demineralized Whey Using Kluyveromyces marxians Naoki Yamahata 1 , Yosuke Toyotake 1 , Satomi Kunieda 2 , Mamoru Wakayama 1* 1 Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Shiga, Japan 2 Department of Gastronomy Management, College of Gastronomy Management, Ritsumeikan University, Shiga, Japan * Corresponding Author: Mamoru Wakayama, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525- 8577, Japan, Tel: 81775612768; E-mail: wakayama@sk.ritsumei.ac.jp Received: 08 January 2020; Accepted: 20 January 2020; Published: 11 February 2020 Citation: Naoki Yamahata, Yosuke Toyotake, Satomi Kunieda, Mamoru Wakayama. Optimal Fermentation Conditions and Storage Period of Fermented Beverages Made from Demineralized Whey Using Kluyveromyces marxians. Journal of Food Science and Nutrition Research 3 (2020): 001-017. Abstract Fermented beverages made from demineralized whey (DMW) as a starting material have a higher sensory acceptability compared to those made from raw whey (RW). Here we investigated the optimal fermentation conditions, namely, temperature and initial pH, and storage period of fermented DMW-based beverages. The 20% w/v DMW solutions were fermented with pure cultured Kluyveromyces marxianus at various temperatures and initial pH values. Multiple sensory evaluations, such as an acceptance test, a descriptive test, and a preference ranking test, were conducted to determine the optimal initial pH and storage period. The final ethanol concentrations at selected fermentation temperatures were 9.6% v/v at 20°C, 9.6% at 25°C, 9.5% at 30°C, 5.8% at 35°C, and 3.6% at 40°C, and the fermentation rate was the highest at 30°C. No differences were observed in either fermentation or sensory characteristics at selected initial pH values (pH 7, pH 6, and pH 5). The optimal fermentation conditions were found to be a fermentation temperature of 30°C and an initial pH of pH 7. Although the preference for DMW-based beverages gradually decreased with storage, the storage period was assessed to extend to 4 weeks. These results indicate that approaches other than fermentation conditions, such as carbonation, aging, and