Evaluasi Pengawet untuk Nira Kelapa (Cocos nucifera L.)

Abstract

Palm sap obtained from tapping palm bunches of coconut flowers. Palm sap rich in sugar with it content apporiximately 11% that make it is easily fermented and decrease its quality. This study aims to obtain an effective antimicrobial formula used to inhibit degradation of palm sap quality. The preservatives used were of ethyl paraben, potassium sorbate, sodium sulfite, and nisin as a single agent or their mixture. Evaluation was done in following steps: (1) evaluation of single preservative toward lactic acid bacteria and yeast, (2) evaluation of preservatives toward lactic acid bacteria and yeast using coconut sap as medium, (3) evaluation the most efficacy preservative toward a mixture of lactic acid bacteria and yeast using coconut sap as medium. Based on the results, the mixture of ethyl paraben+potassium sorbate and ethyl paraben+sodium sulfite could inhibit the growth of yeast, and nisin could inhibit the growth of lactic acid bacteria, and preserve the pH value. When the initial contamination was high (±106 cfu/mL), the mixture of preservatives which could be used were: ethyl paraben 750 ppm + potassium sorbate 250 ppm + nisin 25 ppm; ethyl paraben 750 ppm + potassium sorbate 250 ppm + nisin 50 ppm; ethyl paraben 750 ppm + potassium sorbate 250 ppm + nisin 100 ppm; ethyl paraben 750 ppm + sodium sulfite 125 ppm + nisin 50 ppm; ethyl paraben 750 ppm + sodium sulfite 125 ppm + nisin 100 ppm. However, when initial contamination was lower (±104 cfu/mL), the following mixture of preservatives ethyl paraben 375 ppm + potassium sorbate 125 ppm + nisin 50 ppm were effective to preserve coconut sap.