THE IMPACT OF SALT CONCENTRATION DURING PROLONGED TEMPE FERMENTATION ON CHEMICAL, MICROBIAL, AND SENSORY PROPERTIES
Anggit Woro Kinasih, Irma Novita Faiqotur Rosidah, Lilis Nafi^atul Hidayah, Lailatul Fauziyah, Wardayu Puspita, Umi Purwandari

University of Trunojoyo Madura

Abstract

Over ripe tempe are used in Indonesian cuisine as main raw material or as flavouring agent. Over ripe tempe showed higher concentration of hydrolysis products such as amino acids. This work deal with increasing amino acids content in over ripe tempe by prolonging fermentation using high salt environment. Mature tempe was mixed with 5 and 10% table salt (w/w) and then fermented for 3 weeks at room temperature. Control treatment was tempe with no salt addition. Titratable acidity, pH, moisture content, microbial cells concentration, and sensory properties were examined. Result showed that salt concentration reduced pH from 7.9 in 0 or 5% salt tempe, to 7.1 for 10% salt tempe. Fermentation time affected pH and titratable acidity. By the progress of fermentation, pH increased from 6.8 to 8, while titratable acidity increased from 0.02 to 0.05%. Titratable acidity increased by salt concentration, but not statistically significant. Similarly, concentration of microbial cell also increased by fermentation time, but not significant. Salt concentration seemed to affect cell concentration, but this needed further studies to determine types of microbes especially spoilage and halophilic bacteria. Moisture content was not significantly different among samples across salt concentration and fermentation time. Result of sensory analysis showed that tempe was between ^very much disliked and not liked^ with 5 and 10% salt showed higher hedonic score for aroma although not significantly, and both samples showed significantly low aroma intensity. Prolonged fermentation of tempe in salt environment seemed to alter amino acids profile, and this this could be used to explore amino acids production in tempe to improve its functionality.

Keywords: tempe, fermentation, salt, amino acids, sensory.

Topic: Food science and biotechnology