Sustainable Materials Based on Cellulose from Food Sector Agro-Wastes

Biopolymers exhibit unique properties and can be produced from plants’ and crops’ wastes. Cellulose has beenused for the production of sustainable materials, nevertheless due to the difficulty inherent to its extraction,several methods have been studied in order to optimize the process. Therefore, this paper reports the extractionof natural polymers from food sector agro-food wastes, including cellulose, following a green chemistry aproach.The cellulose extracted from pumpkin peel was acetylated and dispersed in a polylactic acid (PLA) matrix. Thedeveloped materials were characterized in terms of their structure, morphology and thermal stability. Theresults demonstrated the efficient chemical modification of cellulose and confirmed its good dispersion withinthe PLA matrix.

Potential aspect of rice husk biomass in Australia for nanocrystalline cellulose production

Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.

Enhancement of bioactives,functional and nutraceutical attributes of banana peels and de-oiled groundnut cake through submerged fermentation employing Calocybe indica

In the current study,agro-industrial waste(banana peels and de-oiled groundnut cake)was valorised through submerged fermentation employing Calocybe indica.The fermented agro-waste revealed an increase in Ergosta-compounds,(3.57%),which include Ergosta-5,7,9(11),22-tetraen-3-ol,(3.beta.,22E)-(1.87%),Ergosta-5,7,22-trien-3-ol,(3.beta.,22e)-(1.24%)and Ergosta-7,22-dien-3-ol,(3.beta.,5.alpha.,22E)-(0.46%).A reduction of phytic acid(26.25-6.84 mg/100g),oxalate(81.82-18.69 mg/100g),water holding capacity(34.29-30.97 ml/g),least gelation concentration(18-12.5%),bulk density(6.82-2.28 g/ml)and swelling volume(9.5-6.1 ml/g)with an increase inβ-glucan(8-24.57%),dispersibility(78.27-92.92%),oil holding capacity(0.59-1.73 ml/g),valine(ten-fold)and threonine(four-fold)seen in the fermented product makes it suitable for the food industry.GC-MS analysis confirmed the enriched levels of bioactive compounds namely,(S)-(-)-Perillyl alcohol,α.-Longipinene,isozonarol,widdrol,hydroxy valerenic acid,reynosin,β-Eudesmol,lupenone,etc.in fermented agro-waste mixture.The valorised agro-waste-mycelia mixture can be used as a potential nutraceutically enriched health supplement in the food and pharma industries.

Chemical and Microstructural Effects of Different Calcinating Temperatures on Selected Pozzolans

Recent researches show that agricultural wastes can be reuse as pozolans;this contributes to our environmental sustenance. The need to successful carry out proper analysis contributes significantly to improving the overall use of the discovered pozolans. Therefore, this research aims to investigate the micro-structural and chemical analysis of some selected pozzolans at different calcinating temperatures. Rich husk ash (RHA), groundnut shell ash (GSA), locust beans pod ash (LBPA) and bamboo leaf ash (BLA) were obtained;their chemical and microstructural analysis at different calcinating temperatures (500°C, 600°C and 700°C) were carried out using X-ray fluorescence and scanning electron microscope. The results show that the optimum calcinating temperatures considering the microstructure and chemical composition of RHA, BLA and LBPA were 700°C, 500°C and 600°C respectively. These pozzolans were also classified according to ASTM 618 requirement.

Identification of novel bioactive proanthocyanidins with potent antioxidant and anti-proliferative activities from kiwifruit leaves

Agro-wastes contribute major social,economic,and environmental challenges for food production and circular economy systems.The current increasing demand for clean label food production and use of natural bioactive compounds could turn these challenges into opportunities providing avenues for proper utilization of agro-wastes to produce valuable products.This study aimed to investigate the potential use of kiwifruit(Actinidia chinensis)leaves as a source of proanthocyanidins(PAs)bioactive phenolic phytochemicals.Kiwifruit leaves PAs were extracted,purified,identified,and evaluated for their antioxidant and anti-proliferative activities.The structural composition of the purified PAs was characterized using HPLC-QTOF-MS/MS and MALDI-TOF-MS.The results showed that purified kiwifruit leaves PAs(PKLPs)comprised mainly procyanidins,propelargonidins,and prodelphindins ranging from dimers to hexamers with(epi)catechin as terminal units and(epi)afzelechin or(epi)gallocatechin as dominant extension units.This study reports the structure of novel PKLPs monomer fractions was unique compared to the PAs that extracted from the other plant sources.The PKLPs exhibited higher phenolic content than the skin and flesh of several kiwifruit cultivars.Moreover,the PKLPs exhibited higher in vitro antioxidant activity in chemical-based(DPPH,ABTS,and FRAP)assays and H2O2-induced injury cell model than ascorbic,Trolox,and catechin(p<0.01).A remarkable dose-dependent anti-proliferation activity(IC_(50)=186.04±2.61μg/mL)against HepG2 cells was observed.In conclusion,this study demonstrated that kiwifruit leaves waste could serve as a sustainable and low-cost source of PAs,a group of multi-functional bioactive compounds that plays a key role in the food and pharmaceutical industries.