Method Optimization Study on Isolation of Volatile Compounds by Headspace Solid-Phase Microextraction (HS-SPME) from Custard Apple (<i>Annona squamosa</i>L.) Pulp.

Aroma is an important quality parameter, which can help in delaying degradative processes and hence understanding the volatile compounds that are part of an aroma is extremely important. Thus, the aim of this study was to isolate the volatile compounds present in custard apple (Annona squamosa L.) pulp by solid-phase microextraction (SPME) technique using 3 different fibers (DVB/CAR/PDMS, PDMS and PDMS/DVB). An experimental design was set up to evaluate the best extraction conditions wherein the variables were extraction temperature (minimum 28°C, maximum 62°C), ionic strength (minimum 0, maximum 30.0%) and sample concentration (min 1, max 99.0%). The separation of volatiles was achieved in chromatographic columns of different polarity (polar and non-polar) while identification of volatile compounds was performed by high resolution gas chromatography system coupled with mass spectrometry. The results obtained using 3 different fibers revealed the isolation of 71 compounds with fiber DVB/CAR/PDMS, while only 30 and 21 compounds were isolated using fibers PDMS/DVB and PDMS, respectively. The major classes of compounds identified were terpenes, esters, alcohols and aldehydes. Optimum conditions for obtaining higher number of volatiles for non-polar column were 45°C for extraction temperature, 15% of sodium chloride and 50% of pulp amount which resulted in isolation of a maximum of 78 peaks.

Effect of proteases on water-soluble and fat-soluble aroma precursors of goat visceras protein hydrolysate

This study investigated the action of proteolytic enzymes in the production of goat viscera hydrolysates,and their flavoring potential.The study focus the production of flavor precursor molecules and the formation of volatile compounds resulting from four hydrolysis treatments:HA-Alcalase®,HF-Flavourzyme®,HN-Neutrase®,and HFN-Flavourzyme® and Neutrase®.The highest degree of hydrolysis (26.74%),number (23 volatiles) and concentration of volatile compounds (274.0 μg/L) were obtained with the action of Alcalase.The main classes of volatile compounds identified in hydrolysates included acids,aldehydes,pyrazines,terpenes and Streacker aldehydes.Amino acids,sugars and fatty acids were identified with higher concentrations in HF and HFN hydrolysates due to the low participation of these precursors in the formation of volatile compounds.Therefore,the use of Alcalase in the proteolysis of goat viscera stood out compared to other enzymes,providing impacting aroma compounds,such as pyrazines,for meat flavor.