Abstract
Coconut water (CW) is a clear, nutritive liquid found as the coconut endosperm of green coconuts such as Cocos nucifera L., and its widespread consumption owes to its unique composition of sugars, minerals, vitamins, enzymes, and hormones. Probiotic fermentation of CW may facilitate the development of an improved functional beverage with probiotic benefits; therefore, we aimed to produce a fermented CW beverage using the potential probiotic Lactobacillus casei L4. CW was fermented with L. casei L4 for 48 h at 35°C, and the pH, organic acid-production rate, antioxidant activity, antibacterial activity, sugar, mineral, vitamin B12 levels, and total viable bacteria counts were investigated at 24 and 48 h. We demonstrated that the fermentation of CW with probiotic lactobacilli increased the cell viability count. Vitamin B12 production was highest in the extracellular environment at 48 h (11.47 μg/mL), while the total phenolic content was significantly (p < 0.05) higher in the fermented CW at 48 h (72.1 μg/mL gallic acid equivalents) than observed with the other investigated groups or time points. The fermented materials exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activities at 48 h (58.4 and 69.2%, respectively). The levels of most minerals remained unchanged in the fermented CW, except for calcium, manganese, phosphorus, and sodium. Furthermore, the culture supernatant from fermented CW inhibited the growth of foodborne pathogens such as Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhi, although the degree of inhibition varied between the species. Moreover, adding 15% honey and artificial coconut flavor to the fermented CW resulted in a better-tasting product, as demonstrated by a sensory-evaluation test. The obtained results indicated that the CW product fermented by L. casei L4 may be used as a novel functional beverage containing both electrolytes and probiotics, and can serve as a good vehicle for preparing a wider range of novel products.
Highlights
The coconut Cocos nucifera L. belongs to the Arecaceae (Palmae) family and is an important member of the monocotyledons, which are grown throughout tropical and sub-tropical regions (Manivannan et al, 2018)
Coconut water (CW) fermented with Lactobacillus acidophilus and L. casei had considerably high viability, with cell counts of 5.04 × and 1.80 × colony-forming units (CFU)/mL, respectively, after 28 days of storage at 4◦C (Lee et al, 2013)
The cell concentrations in the fermented CW after 48 h were above the minimum recommended for a probiotic product (6 log CFUs/mL based on a daily dose of 100 mL) (Sanders and Huis In’t Veld, 1999)
Summary
The coconut Cocos nucifera L. belongs to the Arecaceae (Palmae) family and is an important member of the monocotyledons, which are grown throughout tropical and sub-tropical regions (Manivannan et al, 2018). CW is classified as tender CW (TCW) or matured CW (MCW), based on the harvest time (Zhang et al, 2018). In the tropics, TCW is consumed primarily as a sports drink (Cappelletti et al, 2015), whereas MCW is generally discarded, because only coconut meat is used for various culinary purposes. Edible coconut parts and various value-added products contain high levels of phenolic and flavonoid compounds with antioxidant potential (Arivalagan et al, 2018), and (+)-catechin and (−)-epicatechin were reported in CW as well (Chang and Wu, 2011). The use of CW to prepare fermented beverages has only been rarely reported (Lee et al, 2013; Prado et al, 2015; Kantachote et al, 2017; Zhang et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
