Conversion of Potato Peel Waste to Single Cell Protein by an Acidophilic Fungus

The aim of this research was to convert potato peel waste (PPW) to single cell protein (SCP), and to extract valuable phenolic compounds from the spent medium. PPW is an abundant by-product of potato processing industry, consisting mostly of starch, fibre and protein in a form of watery sludge. The PPW from a chip manufacturing plant was pre-treated with sulphuric acid, and used as a substrate for an acidophilic Scytalidium acidophilum fungus under non-aseptic conditions. The produced SCP had a promising amino acid composition to be used in animal feed. Phenolic compounds were not recovered from the spent medium, most likely due to the low pH in the medium. The present findings suggest that PPW is a suitable raw material for acidophilic SCP production, whilst the extraction of phenolic acids would require milder cultivation conditions or separation before pre-treatments of SCP production. The BOD5 of the PPW was reduced by in 98% due to fungal cultivation. Thus the feed production also served as an efficient means for reduction of organic load in the PPW.

Utilization of fruit waste for H_(2)-rich syngas production via steam co-gasification with brown coal

In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.

Assessing the bioactivity,cytotoxicity,and rheological properties of pectin recovered from citrus peels

The recovery of pectin from citrus peel waste for application in the food,nutraceutical,pharmaceutical,and medical industries has attracted much interest.It has been postulated that the presence of polyphenols,sometimes regarded as an impurity,in extracted pectin might confer enhanced biological property.This research study aimed at investigating the physicochemical and biological properties(antioxidant,enzyme inhibitory,and cytotoxic properties)of pectin extracted from the alcohol insoluble residues of the peel waste of grapefruit,lime,and lemon as well as the pectin recovered from untreated peel waste.The rheological behavior of the pectin samples was also evaluated.High methoxyl pectin with galacturonic acid content greater that 60%was recovered from the different raw materials.Pectin obtained from untreated material possessed high phenolic content(19.83-5.94 mg gallic acid equivalent/g sample)and showed higher antioxidant activity.Inhibition against pancreatic cholesterol esterase,pancreatic lipase,andα-glucosidase was observed and pectin enriched with polyphenol showed higher activity.Addition of pectin samples to healthy Vero cells enhanced proliferation and did not show cytotoxic effect.Pectin solutions extracted from untreated lime and untreated grapefruit presented highest viscosity and elastic modulus,which were comparable to those obtained for commercial high-methoxyl pectin.Pectin extracted from lime,lemon,and grapefruit peels possessed interesting biological and viscoelastic properties,which can be exploited for development of novel bioproducts.