Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Chemical and Biochemical Properties of Verjuice Obtained from Vitis labrusca Grapes by Using Different Extraction Methods(MDPI (Basel, Switzerland), 2025-10-28) Soares LDS; Sant’Anna V; Leães FL; Weber FH; Furlan JM; Clerici NJ; Brandelli A; Crepalde LT; Dupas de Matos A; Parsons JGVerjuice, a green grape juice traditionally produced from grapes obtained through thinning, represents a sustainable alternative for the utilization of viticulture by-products. No standardized methods of production are utilized to make verjuice, highlighting the need for further research. This study evaluated three extraction methods—pressing extraction (PE), steam extraction (SE), and centrifuge juicer extraction (CJE)—to produce verjuice from three Vitis labrusca varietals (Bordô, Concord, and White Niágara). Physicochemical parameters, volatile compounds (VOC), total polyphenol content, antioxidant and anti-hypertensive activities were analyzed. Extraction method and grape varietal influenced physicochemical composition, antioxidant capacity, and VOC. The SE method resulted in higher yields but lower polyphenolic content, while the CJE was more efficient in extracting phenolic compounds and preserving antioxidant properties. Higher concentrations of malic acid were observed in verjuice extracted by PE and CJE methods from Bordô and Concord grapes, while higher tartaric acid content was found in Bordô and Niágara grapes extracted by CJE. Within grapes, verjuices presented wider volatile profile than those described in the literature, and CJE and PE methods yielded higher amounts of VOC. Thus, V. labrusca presents great potential to produce verjuices and CJE shows to be an efficient alternative to the pressing method.Item Gymnema lactiferum: A Review of Its Traditional Applications, Phytochemical Constituents, and Biological Properties(Wiley Periodicals LLC, 2024-10-16) Weerasinghe DMKP; Brough L; Everett DW; Rashidinejad AHumanity has a longstanding reliance on natural plants for medicinal purposes, and Gymnema lactiferum (G. lactiferum) has emerged as a medicinal plant with deep-rooted traditional usage. Throughout history, this plant has been an integral part of traditional medical systems, demonstrating diverse therapeutic effects. Notably, among these effects is its ability to decrease blood glucose concentration in diabetic patients, impart cooling effects, serve as an anabolic and rehydrating agent, stimulate spermiogenesis, and exhibit wormicidal properties. Furthermore, G. lactiferum has been used in treating conditions such as hemorrhoids cancers, anorexia, and as a cardiac stimulant. The primary objective of this review is to comprehensively gather and critically assess research findings regarding the medicinal properties of G. lactiferum, specifically emphasizing the bioactive compounds responsible for these properties. Previous studies have documented the presence of various phytochemicals in G. lactiferum, which are associated with some biological activities, including antioxidative, anti-hyperglycemic, cholesterol-regulating, and anti-inflammatory properties. Additionally, this review explores potential future applications for this plant. Beyond its medicinal significance, extracts derived from G. lactiferum demonstrate promise for future nutritional applications. This review highlights the potential use of G. lactiferum as an herbal medicine by critically assessing research on its medicinal value.Item Optimizing catechin extraction from green tea waste: Comparative analysis of hot water, ultrasound-assisted, and ethanol methods for enhanced antioxidant recovery(Wiley Periodicals LLC, 2024-04-08) Athirojthanakij W; Rashidinejad AThis study aimed to develop an efficient method for the extraction of bioactive compounds from green tea waste (GTW) toward its potential application in the food industry. GTW, which is generated during the harvesting and processing of green tea products, accounts for a global annual loss of nearly 1 million tonnes. Notably, this waste is rich in polyphenolic compounds, particularly catechins, which are renowned for their significant health benefits. We assessed the optimization of catechin extraction from GTW employing hot water extraction (HWE), ultrasound-assisted extraction (UAE), and ethanol extraction (EthE) techniques at different sample-to-solvent ratios (1:100, 1:50, and 1:20 w/v). The extraction temperature was set at 80°C for both HWE and UAE; however, for EthE, the temperature was slightly lower at 70°C, adhering to the boiling point of ethanol. High-performance liquid chromatography was used to determine the extraction efficiency by quantifying various catechins (i.e., catechin, epicatechin [EC], epicatechin gallate [ECG], epigallocatechin [EGC], and epigallocatechin gallate [EGCG]). In terms of the concentration for individual catechins, EC was found to be the highest concentration detected, ranging from 30.58 ± 1.17 to 37.95 ± 0.84 mg/L in all extraction techniques and ratios of solvents, followed by EGCG (9.71 ± 1.40–20.99 ± 1.11 mg/L), EGC + C (7.95 ± 0.66–12.58 ± 0.56 mg/L), and ECG (1.85 ± 0.71–6.05 ± 0.06 mg/L). The findings of DPPH (2,2-diphenyl-1-picryl-hydrazyl) free radical assay illustrated that HWE demonstrated the highest extraction efficiency at all ratios, ranging from 61.41 ± 1.00 to 70.36 ± 1.47 mg/L. The 1:50 ratio exhibited the highest extraction yield (25.98% ± 0.75%) compared to UAE (24.16% ± 0.95%) and EthE (22.59% ± 0.26%). Moreover, this method of extraction (i.e., HWE) produced the highest total catechins and %DPPH reduction. Consequently, HWE was the most efficient method for extracting catechins from GTW, underscoring its potential for valorizing waste within the food manufacturing industry.