Valorisation of walnut shell and pea pod as novel sources for the production of xylooligosaccharides.

According to the high interest in agro-industrial waste reutilisation, underutilised lignocellulosic materials, such as walnut shell (WS) and pea pod (PP), come in focus. The aim of this paper was to evaluate WS and PP as sources for the production of xylooligosaccharides (XOS). Hemicelluloses from WS and PP were recovered by combining varying parameters of delignification and alkaline extraction. At optimal recovery conditions, the fractions were further hydrolysed to XOS using GH11 endo-xylanase, by varying time and enzyme concentration. Xylose was predominant in the monomeric composition of the obtained hemicelluloses, building low-branched (arabino)glucuronoxylan, in WS exclusively, while in PP some xyloglucan as well. Delignification was essential for high recovery of total xylose from the materials, up to at least 70 %. High xylan conversions were obtained for 24 h hydrolysis, resulting in xylobiose and xylotriose when using low enzyme concentration, while in xylose and xylobiose with high enzyme concentration.

Longan (Dimocarpus longan) and lychee (Litchi chinensis): Functional ingredients in chocolate pralines.

Fresh and half-dried fruits of lychee (Litchi Chinensis) and longan (Dimocarpus longan) were processed by air drying and implemented in diverse forms as fillings in order to produce chocolate pralines. Both dried fruits and chocolate pralines were characterized with total polyphenols, proanthocyanidins, flavan-3-ols and antioxidant capacity (2, 2-diphenyl-1-picrylhydrazyl, 2, 2-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic acid) were determined by spectrophotometric and sensory analyses by quantitative descriptive analysis. Specific polyphenolic compounds were quantified using high-performance liquid chromatography coupled with photodiode array detector. The bioactive content and profile of chocolate pralines produced with the addition of longan and lychee were not significantly altered when compared to plain chocolate, but the sensory analysis revealed a preference for lychee-containing pralines, due to characteristic fruity sensory properties. Since longan and lychee fruits are still underutilized as raw materials and ingredients in food production, preservation by drying and incorporation into new products may enable their popularization and increase functional food production. PRACTICAL APPLICATIONS: Since both longan and lychee are still underutilized as raw materials and ingredients in food production, preservation by drying and incorporation into new products may enable their popularization and increase functional food production.