Kajian potensi asetat, natrium benzoat, dan kalium sorbat sebagai pengawet pada tahu

Abstract

Tofu is one of Indonesian traditional food which is made from soybeans (Glycine max). Tofu stored in the refrigerator has shelf life for about 2 days and only a half day when it stored at ambient temperature. This is the reason why illegal practice of the using formalin has occured in Indonesia. The objective of this research was to evaluate the capability of sodium benzoate, potassium sorbate, and acetic acid as preservatives for tofu. The expected result is giving an alternative of method in preserving tofu with legal food additive. The concentration of sodium benzoate and potassium sorbate that was used in this research is 40% of ADI. Tofu was divided into five main treatments, tofu that soaked in water, acetic acid, acetic acid-sodium benzoate, acetic acid-potassium sorbate, and acetic acid-sodium benzoate-potassium sorbate. Several tests such as, texture analysis, total plate count (TPC), pH measurement, color measurement, and organoleptic test, were conducted to measure the effectivity of each preservative to prolong the shelf life of tofu. TPC assay showed that all of the combinations of preservatives were effective to reduce the number of microbes. The texture of tofu became soften after soaked in acetic acid and analyzed using Texture Analyzer. The result of texture analysis showed that the combination of acetic acid-sodium benzoate had the softest texture (0.46 N) compared to the other treatments. pH measurement showed that acetic acid had the lowest value (4.16) compared to the other treatments. The result of the research showed that acetic acid 1.5% (v/v) did not have the capacity as preservative for tofu. The use of acetic acid 1.5% (v/v) caused sour taste that made tofu could not be accepted by consumers. However, all of the combination of preservatives showed good effect in preserving tofu when stored at room temperature. Soaking sour tofu in 3% (w/v) salt solution for 3 minutes could increase the acceptance of consumers.