No abstract

a b s t r a c tThe influence of headspace solid-phase microextraction (HS-SPME) variables, namely, sample concentration, salt concentration and sample amount, on the equilibrium headspace analysis of the main volatile flavor compounds released from soursop was investigated. A total of 35 volatile compounds, comprising 19 esters, six alcohols, three terpenes, two acids, two aromatics, two ketones and an aldehyde, were identified. The results indicated that all response-surface models were significantly (p < 0.05) fitted for 10 target volatile flavor compounds. The results further indicated that more than 65% of the variation in the equilibrium headspace concentrations of target volatile flavor compounds could be explained by the final reduced models, with high R 2 values ranging from 0.658 to 0.944. Multiple optimization results showed that extraction using a 76.6% (w/w) sample concentration, 20.2% (w/w) salt and 8.2 g of blended soursop pulp was predicted to provide the highest overall equilibrium headspace concentration for the target soursop volatile flavor compounds.

The functional properties and biological aspects of a natural biodegradable biopolymer depend on its chemical and molecular structure. In this study, the effect of different drying processes on the chemical and molecular structure of the natural biodegradable biopolymer from durian seed was investigated. The chemical structure was analyzed by assessing the carbohydrate profile, protein, amino acid composition, moisture, and ash. Molecular weight (Mw), number average molecular weight (Mn), Mw/Mn ratio and mass recovery were assessed by using a size-exclusion chromatography coupled to multi angle laser lightscattering (SEC-MALS). The present study revealed that main monosaccharides in the chemical structure of differently dried durian seed gums were galactose (50.1-64.9%), glucose (29.4-45.7%%), arabinose (0.11-0.89%), and xylose (0.019-0.86%). The protein analysis indicated the presence of a low amount of the protein fraction (3.2-3.9%) in the chemical structure of the biopolymer from durian seed. The most abundant amino acids in the chemical structure of durian seed gum were leucine (31.78-43.02%), lysine (6.23-7.78%), aspartic acid (6.45-8.58%), glycine (6.17-7.27%), glutamic acid (5.43-6.55%), alanine (4.60-6.23%), and valine (4.49-5.52). The current study exhibited that the biodegradable biopolymer from durian seed was a heteropolysaccharideprotein complex with medium Mw ranging from 1.06 × 105 to 1.15 × 105 (g/mol).

No abstract