Variation of the Phytochemical Constituents and Antioxidant Activities of Zingiber officinale var. rubrum Theilade Associated with Different Drying Methods and Polyphenol Oxidase Activity

Abstract

Abstract:The effects of different drying methods (freeze drying, vacuum oven drying, and shade drying) on the phytochemical constituents associated with the antioxidant activities of Z. officinale var. rubrum Theilade were evaluated to determine the optimal drying process for these rhizomes. Total flavonoid content (TFC), total phenolic content (TPC), and polyphenol oxidase (PPO) activity were measured using the spectrophotometric method. Individual phenolic acids and flavonoids, 6-and 8-gingerol and shogaol were identified by ultra-high performance liquid chromatography method. Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used for the evaluation of antioxidant activities. The highest reduction in moisture content was observed after freeze drying (82.97%), followed by vacuum oven drying (80.43%) and shade drying (72.65%). The highest TPC, TFC, and 6-and 8-shogaol contents were observed in samples dried by the vacuum oven drying method compared to other drying methods. The highest content of 6-and 8-gingerol was observed after freeze drying, followed by vacuum oven drying and shade drying methods. Fresh samples had the highest PPO activity and lowest content of flavonoid and phenolic acid compounds compared to dried samples. Rhizomes dried by the vacuum oven drying method represent the highest DPPH (52.9%) and FRAP activities (566.5 µM of Fe (II)/g DM), followed by freeze drying (48.3% and 527.1 µM of Fe (II)/g DM, respectively) and shade drying methods (37.64% and 471.8 µM of Fe (II)/g DM, respectively) with IC 50 values of 27.2, 29.1, and 34.8 µg/mL, respectively. Negative and significant correlations were observed between PPO and antioxidant activity of rhizomes. Vacuum oven dried rhizomes can be utilized as an ingredient for the development of value-added food products as they contain high contents of phytochemicals with valuable antioxidant potential.

Traditional Usages and Phytochemical Screenings of Selected Zingiberaceae from Central Sulawesi, Indonesia

“…Results reported herein are expected to enhance those of similar studies reported previously, for example, the essensial oils from rhyzome of Zingiber officinale var.rubrum, Zingiber amaricans, Kaempferia galanga and Boesenbergia pandurata, 29 the chemical constituents of the aerial parts of Etlingera brevilabrum, 30 35 on phytochemical screening and evaluation of its antimicrobial activities of Zingiber officinale, 36 phytochemical and antimicrobial activities of turmeric, 37 Ghasemzadeh et al (2016) on variation of phytochemical constituents and antioxidant activity of Zingiber officinale var. rubrum 38 and Azam et al (2014) on the phytochemical screening and antipyretic effect of Curcuma zedoria Rosc. 39…”

Óleos essenciais no controle de Botrytis cinerea: influência na qualidade pós-colheita de uvas ‘Rubi’

“…O escurecimento dos frutos acarreta efeitos negativos na coloração e no sabor das bagas de uva (Ghasemzadeh et al, 2016). Para Zimdars et al (2017), a intensidade dos impactos na extensão da deterioração da cor depende da atividade das enzimas também secretadas por B. cinerea.…”

Changes in the Content of Chemical Elements in the Muscle Tissue of Broilers on the Background of Plant Extract and Tetracyclines

“…Some substances enhance the flavor and palatability of feed, which improves feed intake and productive performance [15], [16]. This result can be related to several biological activities, such as antioxidant, antimicrobial and flavor enhancer effects [17], [18].…”