Production and analyses of Dokong (Lansium Domesticum) and Rambutan (Nephelium Lappaceum) fruits vinegars.

Nowadays, there was a high demand of fruits vinegars in the market, however, most of these fruits vinegars such as apple cider vinegar, date vinegar and pomergranate vinegar were imported from other countries. Thus, the aim of this research is to produce vinegar from local fruits which are dokong and rambutan using a traditional natural fermentation process. Physicochemical analysis, total colony count, proximate analysis, estimation of mineral element content, heavy metal content and economic feasibility was carried out for the vinegar. The physicochemical analysis for dokong and rambutan vinegar were; pH (3.88 and 3.48), total soluble solid (6.06 and 16.44°Brix), titratable acidity (3.56% and 7.45%), alcohol content (0.40% and 0.48%) and acetic acid content (17.17% and 35.11%). For total colony count of dokong vinegar, the highest value on PDA was on day 21 which was 6.25 x 103 ± 1.73 cfu/ml while on NA the colony was highest on day 21 which was 2.29 x104 ± 6.35 cfu/ml while for rambutan vinegar; the highest value on PDA was on day 14 which was 4.16 x 104 ± 2.31 cfu/ml while on NA the colony was highest on day 35 which was 2.08 x 104 ± 5.77 cfu/ml. The proximate analysis of dokong and rambutan were; moisture content (92.59% and 81.47%), protein (0.18% and 0.34%) and fat (0.59% and 0.07%). Moreover, the mineral constituent for these fruits vinegars contained Potassium (209.10-387.67 mg/kg), Sodium (97.47- 334.20 mg/kg), Calcium (0 – 137.90 mg/kg), Magnesium (11.52 – 161.40 mg/kg), Manganese (0.13-2.05 mg/kg), Zinc (0.52-80.99 mg/kg) and Iron (0.93 –8.09 mg/kg). Trace elements of heavy metals, Lead, Cadmium and Chromium were not detected in all of samples. Copper ranges between (0.14-1.19) ppm and Nickel (0.15- 5.60 ppm) were detected in all samples. For the economic feasibility, dokong vinegar able to gain the gross profit in year 1 which is RM 12, 677 while rambutan vinegar was RM 38, 803. The production of dokong and rambutan vinegar is a profitable investment because the net present value for both of vinegar showed the positive result which means this investment should be continue. Overall, dokong and rambutan vinegar provide higher or equal standard with the commercialized vinegar which is apple cider and nipah vinegar in terms of quality and nutritients and also provide a beneficial investment. As conclusion, it is possible to produce vinegar from dokong and rambutan where all the parameters such as the pH, TSS, TA, alcohol content and acetic acid content in the range of the international standard protocol for vinegar.