Dede Robiatul Adawiyah

Characterization of arenga starch in comparison with sago starch

The aim of this research was to characterize the composition and physical properties of palm starch obtained from Arenga pinnata in comparison with another palm starch from Metroxylon sago. The amylose contents of both starches were not significantly different. Peak gelatinization temperature was also similar at approximately 67 °C, but arenga starch showed a narrower range of gelatinization temperature than sago. The crystallinity and swelling power capacity of arenga starch were lower than those of sago. Arenga and sago starch paste at low concentrations showed shear thinning behavior, and sago formed a more viscous sol/paste than arenga. The sol-gel transition concentration of sago starch paste was found at a lower concentration than arenga starch. At high concentrations, gel from arenga starch was more rigid than that of sago. The breaking properties and texture profile of both starch gels were also clearly different, suggesting that they are suited for different applications.

Relationship between sensory attributes of bakasang (a traditional Indonesian fermented fish product) and its Physicochemical properties

Quantitative descriptive analysis and physicochemical analysis were carried out to assess the relationship of the sensory attributes of bakasang (a traditional Indonesian fermented fish product) to its physicochemical properties. Pearson correlation analysis and partial least-squares regression (PLS-R) were used to analyze the data. Two PLS-R models were established for relating six physicochemical properties to 12 sensory attributes. The first PLS-R model indicated that salty, umami, bitter, and bitter aftertaste showed an excellent correlation to moisture content, water activity (aw), salt content, and free amino nitrogen. The second model indicated that sulphury meaty, overripe cheese, sweaty, and ammonia were positively correlated with the moisture content, aw, salt content, and total volatile bases. A microbiological quality test of this product indicated that it meets the standards of the Indonesian National Standard Quality of fish sauce.

Umami compounds present in low molecular umami fractions of asam sunti – A fermented fruit of Averrhoa bilimbi L.

Salted fermented fruit known as asam sunti (Averrhoa bilimbi L.) in Indonesia has been used as a source of umami taste. This study was aimed to characterize the three types of asam sunti and their water soluble extracts, and to trace the compounds responsible for umami taste in umami fractions. Umami fractions were obtained by ultrafiltration followed by Sephadex G-15 chromatographic separation. The three types of samples could be differentiated by physicochemical and sensory analyses. Low molecular weight fraction had the highest umami intensity. Further chromatographic separation revealed three umami fractions, F-II, III and IV. Umami taste of F-III was due to the presence of free l-glutamic acid at 6 times, while FII and FIV were due to succinic acid at more than 30 times their respective umami thresholds. Organic acid as well as amino acid seemed to play an important role in the intense umami taste of asam sunti.