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Item Influence of fermentation on the quality of Fijian Theobroma cacao beans over two harvest seasons(Taylor and Francis Group, 2024-10-01) Raju RN; Heyes J; Archer R; Chen QTheobroma cacao beans are cultivated in Fiji by smallholder farms in low volumes, mainly for export. Cocoa beans are often processed under ambient conditions by farmers and cocoa processors. Postharvest processing includes natural fermentation from six to ten days in wooden boxes, followed by sun – drying in the open for up to 14 days. The impact of fermentation conditions on key quality parameters of Fijian cocoa beans, such as temperature profile, pH, and total extractable polyphenol content (TPC) are presented in this study. The quality of fermentation was assessed using a standard method, such as a cut test followed by fermentation index (FI) measurement. A temperature increase to 40°C and variations in the pH of the bean mass were evident during natural fermentation. TPC in the cocoa beans was sensitive to temperature and pH. Fermentation was variable due to weather conditions between harvest seasons. The dry season had the best conditions for fermentation as the peak temperature of the bean mass was 40°C and the FI was high (1.39 ± 0.04) There is a need to improve fermentation during the rainy season. This can be achieved by providing training to Fijian cocoa farmers on using better fermentation techniques.Item Enhancing antioxidant property of instant coffee by microencapsulation via spray drying(Editorial Universitat Politècnica de València, 2019-01-18) Sakawulan D; Archer R; Borompichaichartkul C; Cárcel JA; Clemente G; García-Pérez JV; Mulet A; Rosselló CThis study is aimed to improve the antioxidant property of instant coffee by using microencapsulation technique and spray drying. Concentrated coffee extract was mixed with Konjac glucomannan hydrolysate (KGMH) and Maltodextrin (MD). The mixture of coating material and coffee extract was then spray dried at 160 - 180 °C inlet air temperature and at 85-90 °C outlet air temperature. KGMH can preserve retention of phenolic compounds, DPPH scavenging activity and antioxidant activity of FRAP (p<0.05 of instant coffee better than other treatment.Item Enhancing antioxidant property of instant coffee by microencapsulation via spray drying(EDITORIAL UNIVERSITAT POLITÈCNICA DE VALÈNCIA, 2018) Sakawulan D; Archer R; Borompichaichartkul CThis study is aimed to improve the antioxidant property of instant coffee by using microencapsulation technique and spray drying. Concentrated coffee extract was mixed with Konjac glucomannan hydrolysate (KGMH) and Maltodextrin (MD). The mixture of coating material and coffee extract was then spray dried at 160 - 180 °C inlet air temperature and at 85-90 °C outlet air temperature. KGMH can preserve retention of phenolic compounds, DPPH scavenging activity and antioxidant activity of FRAP (p<0.05) of instant coffee better than other treatment.Item Partial Biodegradable Blend for Fused Filament Fabrication: In-Process Thermal and Post-Printing Moisture Resistance(MDPI AG, 9/04/2022) Harris M; Mohsin H; Naveed R; Potgieter J-G; Ishfaq K; Ray S; Guen M-JL; Archer R; Arif KDespite the extensive research, the moisture-based degradation of the 3D-printed polypropylene and polylactic acid blend is not yet reported. This research is a part of study reported on partial biodegradable blends proposed for large-scale additive manufacturing applications. However, the previous work does not provide information about the stability of the proposed blend system against moisture-based degradation. Therefore, this research presents a combination of excessive physical interlocking and minimum chemical grafting in a partial biodegradable blend to achieve stability against in-process thermal and moisture-based degradation. In this regard, a blend of polylactic acid and polypropylene compatibilized with polyethylene graft maleic anhydride is presented for fused filament fabrication. The research implements, for the first time, an ANOVA for combined thermal and moisture-based degradation. The results are explained using thermochemical and microscopic techniques. Scanning electron microscopy is used for analyzing the printed blend. Fourier transform infrared spectroscopy has allowed studying the intermolecular interactions due to the partial blending and degradation mechanism. Differential scanning calorimetry analyzes the blending (physical interlocking or chemical grafting) and thermochemical effects of the degradation mechanism. The thermogravimetric analysis further validates the physical interlocking and chemical grafting. The novel concept of partial blending with excessive interlocking reports high mechanical stability against moisture-based degradation.Item Partial Biodegradable Blend with High Stability against Biodegradation for Fused Deposition Modeling(MDPI AG, 11/04/2022) Harris M; Mohsin H; Potgieter J; Ishfaq K; Archer R; Chen Q; De silva K; Guen M-JL; Wilson R; Arif KThis research presents a partial biodegradable polymeric blend aimed for large-scale fused deposition modeling (FDM). The literature reports partial biodegradable blends with high contents of fossil fuel-based polymers (>20%) that make them unfriendly to the ecosystem. Furthermore, the reported polymer systems neither present good mechanical strength nor have been investigated in vulnerable environments that results in biodegradation. This research, as a continuity of previous work, presents the stability against biodegradability of a partial biodegradable blend prepared with polylactic acid (PLA) and polypropylene (PP). The blend is designed with intended excess physical interlocking and sufficient chemical grafting, which has only been investigated for thermal and hydrolytic degradation before by the same authors. The research presents, for the first time, ANOVA analysis for the statistical evaluation of endurance against biodegradability. The statistical results are complemented with thermochemical and visual analysis. Fourier transform infrared spectroscopy (FTIR) determines the signs of intermolecular interactions that are further confirmed by differential scanning calorimetry (DSC). The thermochemical interactions observed in FTIR and DSC are validated with thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) is also used as a visual technique to affirm the physical interlocking. It is concluded that the blend exhibits high stability against soil biodegradation in terms of high mechanical strength and high mass retention percentage.