Evaluation of postharvest storability of Ponkan mandarins stored at different temperatures

ABSTRACT The effects of storage temperature on postharvest storability, quality attributes and antioxidant enzyme activities of harvested Ponkan mandarins were investigated. Fresh fruits were randomly divided into four groups and stored at different temperatures [5 ± 1 °C (S5), 10 ± 1 °C (S10), 15 ± 1 °C (S15), and 20 ± 1 °C (S20 or control)] for 120 days. The results indicated that, compared with the control fruit, low-temperature storage at 10 °C significantly delayed the increase in fruit decay rate, weight loss, citrus colour index, respiration intensity, relative electrical conductivity, the accumulation of hydrogen peroxide and malondialdehyde, retarded the decline in L* value, retained high contents of total soluble solid, titratable acid, vitamin C, total phenol and total flavonoid, as well as higher activities of antioxidant enzymes – superoxide dismutase, catalase, peroxidase and ascorbic peroxidase. The principal component analysis results showed that low-temperature storage significantly maintained the postharvest quality of Ponkan mandarins, with fruit stored at 10 °C having no significant difference from the fruit stored at 5 °C, but markedly higher than those fruit stored at 15 °C. The comprehensive result of single-factor analysis and PCA showed that 10 °C could be used as the optimum storage temperature for improving the postharvest storability of Ponkan mandarins.

The Effect of Concentration of Beeswax Emulsion on Shelf Life and Quality of Beetroot (Beta vulgaris L.) during Room Temperature Storage

Beetroot (Beta vulgaris L.) is one of the horticultural products that have the potential for development in Indonesia. beetroot contains a high level of betalain and vitamin C, so it can be an antioxidant for cancer. But nowadays, post-harvest handling is not specially noticed by people yet. The aims of this research were to determine the effect of beeswax coating on shelf life and quality of the beetroot and determine the best wax emulsion concentration as beetroot coating. This research was conducted at the Posharvesting Handling Laboratory of the Faculty of Agriculture and Business, Satya Wacana Christian University, Salatiga. The method used Randomized Block Design with 4 treatments and 6 replications. The concentration of beeswax emulsions used in this research is about 4%, 8%, and 12%. The observed parameter was weight loss, respiration, total dissolved solids, water content, and vitamin C. The results show that the treatment with a concentration of 12% of beeswax emulsion is the best result when compared with other treatments. The result also shows the concentration of 12% beeswax emulsion can maintain the storage time and quality of the beetroot.

Aplikasi Zeolit-KMnO4 dan Silica Gel untuk Memperpanjang Green Life Mangga Arumanis (Mangifera Indica L)

Mangoes are harvested when ripe have an "eating quality" that consumers are them in, but quickly reach the senescence phase, making it less profitable for businesses. As a climacteric fruit, the ripening process of mango can be slowed down by using an ethylene adsorber. This study aims to determine the combination of zeolite-KMnO4 and silica gel as ethylene adsorber (EAB) to maintain the green life of ripe The material used is ethylene adsorber (EAB) which is applied to mango arumanis which is packaged with a weight package of 1000±50 g. After the shelf life is reached, the EAB is removed from the packaging and the mangoes are left at room temperature for natural ripening and continued until conditions are not acceptable to consumers. The results showed that the EAB application was able to maintain the green life of mangoes by the scenario of the shelf life both at cold and room temperature storage. Natural ripening of mango was achieved 5 days and 2 days after EAB was removed from the packaging, for cold and room temperature storage, respectively. The length of time until the panellists did not receive it was 20 days for cold storage and 12 days for the room, while the control for cold storage was 6 and 3 days at room temperature

Antioxidative Effect of Sage (Salvia officinalis L.) Macerate as “Green Extract” in Inhibiting the Oxidation of Fish Oil

The aim of the study was to assess the antioxidant effect of concentrated oil macerate of sage (M) as a “green extract” in inhibiting the oxidation of Fish Oil (FO). In the homogenization-assisted maceration process, FO was used as a solvent for the sage active substances to produce M, which was then added to FO (25% w/w) and evaluated for its effect by monitoring the level of oxidation during refrigerated and room temperature storage. The macerate also examined polyphenols, plant pigments, DPPH antioxidant potential, oxidation level and sensory quality. It was shown that the maceration process made it possible to obtain aromatized M, containing polyphenols (carnosic acid, carnosol) and pigments, but with an increased level of peroxides, free fatty acids, compared to the control oil. M showed antioxidant properties and inhibited FO oxidation. It showed the best efficiency in FO during refrigerated storage, in the third month it reduced the level of peroxides by about 9 times, compared to the control. M retains unchanged quality at refrigerated temperature for up to 3 months. Sage macerates are „green extracts” that can be used as effective natural antioxidant additives, following preparation improvements to reduce the amount of peroxide formed.