Impact Of Traditional Processing Research Articles

Insight into aroma dynamic changes during the whole manufacturing process of smoked Lapsang Souchong tea

Smoked Lapsang Souchong tea (SLST) is a distinctive black tea known for its smokey, fruity, and pine flavor. This study analyzed the aroma dynamic changes during the whole manufacturing process of SLST utilizing E-nose, HS-SPME-GC–MS, and HS-SPME-GC-O-MS. Fresh tea leaves primarily contain green and floral volatiles, such as (E)-2-hexenal (OAV 33.41) and linalool (OAV 313.88). Withering and drying processes introduce pinewood smoke-derived phenolic and terpenoid compounds, such as guaiacols (OAV 77.05) and α-terpineol (OAV 1.08), crucial for the tea's smoky and woody aroma. The study further highlights glycoside hydrolysis and lipid oxidation pathways in generating key tea-derived volatiles during fermentation, contributing to the fruity and floral notes in SLST. Pinewood smoke was identified as a major source of smoky volatiles, with longifolene and α-terpineol being unique to pinewood. These findings elucidate the formation pathways of the key volatile compounds and the impact of traditional processing on SLST's aroma profile.

Impact of traditional processing on proximate composition, folate, mineral, phytate, and alpha-galacto-oligosaccharide contents of two West African cowpea (Vigna unguiculata L. Walp) based doughnuts

Doughnuts made from cowpea, a highly nutritious pulse, are frequently consumed in West Africa. As processing may affect their nutritional composition, cowpea processing into two doughnut types (ata and ata-doco) was characterized, and samples collected from 12 producers in Cotonou, Benin. Proximate composition, folate, mineral, phytate, and alpha-galacto-oligosaccharide contents were determined in the raw material, intermediate products, and doughnuts. Mass balance was assessed during ata production to monitor folate and alpha-galacto-oligosaccharides distribution, and to determine what steps most influenced their concentration. Ata was prepared with dehulled-soaked seeds, and ata-doco with whole or partially dehulled, non-soaked and dry-milled seeds. After both types of doughnuts production, lipid content increased by 11–33 times compared with raw seeds, due to oil absorption during deep-frying. Milling led to an increase of iron content by 50–57 % (ata) and 21–75 % (ata-doco production). Alpha-galacto-oligosaccharide contents decreased by 22–57 % after whipping during ata-doco, but not during ata production. The mass balance assessment showed significant reductions of folate (-50 %) and alpha-galacto-oligosaccharides (-33 %) after dehulled seed washing and soaking during ata production. This study showed that the impact of traditional processing on the nutritional value of cowpea-based doughnuts is strong, but highly variable depending on the doughnut type and producers’ practices.