Nutrafoods (2016) 15:111-121 Original Research DOI 10.17470/NF-016-1030-2 Process optimization for the preparation of apple tea wine with analysis of its sensory and physico-chemical characteristics and antimicrobial activity against food-borne pathogens Vikas Kumar1, Vinod K. Joshi2, Gitanjali Vyas3, N.S. Thakur2, Nivedita Sharma3 Keywords: Apple, Tea, Apple tea wine, Correspondence to: Saccharomyces cerevisiae, Vikas Kumar Natural fermentation, [email protected] Functional properties Abstract Apple tea wine fermented with S. cerevisiae var. el- lipsoideus had higher sensory scores for most at- Method for preparing apple tea wine using differ- tributes than naturally fermented apple tea wine. ent types of tea at different concentrations were Different treatments were clustered based on tea optimized and the physico-chemical, antimicrobial concentration as a function of fermentation with and sensory characteristics of the wine analysed. All S. cerevisiae var. ellipsoideus unlike the natural fer- characteristics were found to be directly propor- mentation where no clear clustering trend was tional to the concentration of tea fermented natu- observed. The type of fermentation influenced rally or with Saccharomyces cerevisiae var. ellipsoi- the quality of the wine as separate clusters for deus. In both types of fermentation, CTC (crush, the different fermentations were observed during tear and curl) tea-based apple tea wine received combined cluster analysis of the different types of significantly higher quality scores (p≤0.05). Bet- wine. Our results demonstrated that the best apple ter results in terms of ethanol, higher alcohol con- tea wine was made with 4 g CTC tea/100 ml apple centrations and antimicrobial activity were found juice and fermented with S. cerevisiae var. ellipsoi- with 4 g tea/100 ml apple juice than with other deus, and showed potential as a functional product concentrations, particularly 5 g tea/100 ml apple which also demonstrates the medicinal properties juice. All apple tea wines showed antimicrobial ac- of tea. tivity (inhibition zone >7 mm) against Escherichia coli (IGMC), Enterococcus faecalis (MTCC 2729), Introduction Listeria monocytogenes (MTCC 839), Staphylococcus aureus (MRSA 252) and Bacillus cereus (CRI). As economic status has improved, growing interest in health and well-being has resulted in increased intake of natural foods. Tea, a non-alcoholic bev- 1Assistant Professor, Food Technology and Nutrition, School of Agriculture, Lovely Professional University, Phagwara, Punjab erage consumed worldwide and prepared from tea 144411, India leaves (Camellia sinensis L.) is gaining popularity phone: +919418653296 as an important ‘health drink’ and is consumed 2Department of Food Science and Technology, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal by up to two thirds of the world’s population. Pradesh 173230, India. Among the 700 chemical constituents present in 3Department of Basic Sciences, Dr. Y.S. Parmar University of Hor- ticulture and Forestry, Nauni, Solan, Himachal Pradesh 173230, tea leaves, flavonoids, amino acids, vitamins (C, India. E, K), caffeine and polysaccharides are considered Received: September 13, 2015 / Accepted: December 28, 2015 111 EDITORE www.ceceditore.comsrl Nf2_2016_interno.indb 111 28/06/16 10:59 Nutrafoods (2016) 15:111-121 important for human health. The caffeine (3% by crobial activities of fermented tea have been less weight) in tea provides a stimulating effect [1]. studied than its beneficial health properties. These Polyphenols in tea are the most important con- antimicrobial activities develop during the natu- stituents and act as antioxidants, known to play ral microbial fermentation process with tea leaves a significant role in human health. Black tea is as substrates. The antimicrobial components pro- considered to be a good fermentation medium be- duced during the fermentation process have shown cause its infusion contains proteins, amino acids, inhibitory effects against several food-borne and volatile compounds, lipids, enzymes and, more pathogenic bacteria as reported by Sreeramulu et importantly, polyphenols [2]. al. [22]. Its acidity and low alcohol content allow Wine consumed in moderation is considered a kombucha to resist contamination by most air- safe and healthy drink and is an important adjunct borne moulds and bacterial spores. The beverage is to the diet [3]. Different studies have shown the brewed at home so preparation conditions are gen- beneficial effects of wine consumption due to the erally not sterile. However, most tests indicated a presence of phenolics and alcohol, which protect low rate of contamination from spoilage and path- the human body from attack by free radicals and ogenic microorganisms, suggesting that kombucha increase HDL levels, respectively [4, 5]. Phenolic has antimicrobial properties against pathogenic compounds also play a major role in enology as and other harmful microorganisms [23]. Some they are responsible for the colour and flavour of studies have reported that the antimicrobial activ- red and white wine. In addition to their bacteri- ity of kombucha made with a low concentration cidal role, phenolics are responsible for the ‘French of tea (4.4 g/l) was attributable to the acetic acid paradox’ whereby antioxidants and vitamins are content [10]. Indeed, the systematic investigation apparently protective against cardiovascular dis- of Sreeramulu et al. [22] demonstrated that the ease [6]. antimicrobial activity of kombucha was not due to Apple juice has been fermented in Eastern Mediter- organic acids, ethanol, proteins or tannins present ranean areas for more than 2000 years to obtain a in tea or their derivates. pleasant alcoholic beverage [7]. It is also fermented The chemical constituents of tea and the phyto- to produce cider, a sparkling and refreshing fruit- chemical potential of apple juice can both be used flavoured drink consumed in many countries [5, to improve the quality of wine. Siby and Joshi 8], as well as wine and brandy. Kombucha or tea [24] supplemented apple wine with spice extracts cider (a traditional fermented tea product) is often which increased the polyphenolic content and also drunk for medicinal purposes due to the acetic acid enhanced antimicrobial activity. In light of the formed during fermentation and has been used in health benefits of tea, the importance of apples in Russia for several centuries [9]. Alcohol is also pro- the wine industry and the role of different micro- duced during fermentation of kombucha [10]. flora in wine fermentation, the aim of this study The increasing antimicrobial resistance of patho- was to improve the physico-chemical, antimicro- gens isolated from humans and animals, com- bial and sensory properties of apple tea wine pro- bined with the increasing consumer awareness of duced by fermentation with Saccharomyces cerevi- chemical food preservatives, necessitates research siae var. ellipsoideus and by natural fermentation. for more efficient antimicrobials with fewer side- The results of our study are presented below. effects on human health. Different plant extracts were examined for antimicrobial activity against Materials and methods pathogens by Papadopoulou et al. [11]. Tea ex- tracts have exhibited antioxidant [12], antimuta- Materials genic [13, 14], anticarcinogenic [15], antibacterial Apples (Golden variety) were procured from the [16], antiviral [17], antifungal [18] and antitumor local market in Solan (Himachal Pradesh, India). activity [19, 20]. Natural antibacterial agents have Orthodox tea (Dhauladhar, natural organic or- been increasingly applied for the biological pres- thodox Kangra tea) was procured from HPKV, ervation of food in recent years [21]. The antimi- Palampur (Himachal Pradesh, India), herbal tea 112 www.ceceditore.com EDITORE srl Nf2_2016_interno.indb 112 28/06/16 10:59 Nutrafoods (2016) 15:111-121 (Himalayan brew, Kangra special herbal tea) was wines were analysed for different physico-chemical procured from the local market in Palampur, and properties: TSS, titratable acidity (as malic acid), CTC tea (Tajmahal) was procured from the local pH, sugars according to standard methods [25], market in Solan. The yeast strain S. cerevisiae var. and ethanol measured colourimetrically by the po- ellipsoideus (UCD 595) was procured from the In- tassium dichromate method [26]. Volatile acidity dian Institute of Horticulture Research, Bangalore was estimated by the titration methods described (Karnataka, India). Sugar was procured from the by Amerine et al. [27]. The content of higher alco- local market. Pectin esterase was procured from hols was estimated using the method of Guymon M/S Triton Chemical, Mysore (India) and used at et al. [28]. a concentration of 0.5%. The antimicrobial activity of apple juice, apple tea wine and tea cider was determined against all Methods the test microorganisms, that is, Escherichia coli Infusions of tea leaves with apple juice were pre- (IGMC), Enterococcus faecalis (MTCC 2729), Lis- pared by boiling different concentrations of tea in teria monocytogenes (MTCC 839), Staphylococcus apple juice for 3 min at 100°C. The concentra- aureus (MRSA 252) and Bacillus cereus (CRI), by tions (2, 3, 4 and 5 g per 100 ml apple juice) and the well diffusion method [29] under aerobic con- types of tea (CTC, orthodox and herbal) varied, ditions. resulting in 12 different combinations. Infusions A semi-trained panel of judges analysed the sen- were filtered through sieves