BACKGROUND The effects of pulp extraction, thermal treatment and bulk storage of mango (Mangifera indica L.) and pineapple (Ananas comosus L.) pulps for 20 weeks at ambient (28 ± 2 °C) and cold (4 °C) temperatures on the bioactive phytochemicals and antioxidant activity were investigated. RESULTS The contents of total polyphenols in mango (10.5%) and pineapple (5.4%) increased during pulping. The ratio of the degradation rate constants (kd values) (28 ± 2 °C: 4 °C) of vitamin C, polyphenols, Trolox equivalent antioxidant capacity (TEAC) and β‐carotene ranged from 2–4.5 and 1.5–2.7 in mango and pineapple pulps, respectively. The kd values of tannic acid, chlorogenic acid, epicatechin and catechin in mango pulp were 1.5–1.8 times higher under ambient storage than in cold storage. Furthermore, in pineapple pulp, the degradation rates of the same components were 1.6, 1.6, 2.1 and 1.4 times, respectively, faster at room temperature than in cold storage. The bulk storage of pulps at 4 °C provided better retention of health‐promoting compounds than ambient temperature storage for up to 20 weeks. CONCLUSION Bulk storage of mango and pineapple pulp under cold storage conditions (4 °C) is recommended as a better pulp preservation method than storage at ambient (28 ± 2 °C) temperature. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Our study investigated whether the chemical intensity and weight yield of essential oil fraction of Zingiber officinale roscoe was significantly affected by variety, maturity stage or cultivated location in Sri Lanka. Two varieties, Rangoon and Siddha planted in two geographical locations of Sri Lanka were harvested at three maturity stages. Chinese variety was studied as the control. Study revealed that the ginger essential oil (GEO) weight yield decreased with increasing maturity stage. Maturity stage and location of cultivation was significantly affecting GEO weight yield while chemical intensities were significantly affected by maturity stage only. Variety factor was not significantly affecting any of the dependent variables. Interaction effects between factors suggested that Siddha and Rangoon were the best varieties to cultivate in Sri Lanka. Best time to harvest rhizomes was at 5 months maturity for any tested variety. 13 major compounds were identified in Siddha while 12 major compounds were identified in Rangoon. It was suggested that variety Siddha was better than Rangoon from its antibacterial chemical profile and composition.

Fruit juice-based products are potentially high demanded products in Sri Lanka. The research was conducted to estimate the total sugar content in commercially available fruit juice products and to compare the suitability and efficiency of analytical methods: Lane and Eynon titration method and UV-Visible spectrophotometric methods. Further synthetic colorants in the products were identified and compared with the label information. A consumer survey was conducted to elicit information on consumer preference and knowledge on sugar content of the products. Based on the survey, consumers were more concerned about taste (37%), brand name (28%), price (28%), and nutrition value (7%), respectively. Awareness about the Recommended Dietary Allowance (RDA) of sugar, added sugar consumption, and risk of chronic diseases was 49%. Awareness on the color coding system of the products was 68%. The total sugar content of the fruit nectars was determined using both methods. The maximum total sugar level (18.38 g/100 mL) was observed by the titration method, while the maximum total sugar level (18.31 g/100 mL) was measured by the spectrophotometric method in wood apple (Limonia acidissima) nectar in brand No. “1.” The maximum sucrose content (10.57 g/100 mL) was observed in mango (Mangifera indica L.) nectar in the brand No. “1.” Total sugar contents of both tested methods were compared using SAS 9.0 (Randomized Complete Block Design, RCBD). There is no significant difference (P>0.05) between the two testing methods. In conclusion, the Lane and Eynon titration method was identified as the most effective method for analysis of the total sugar in fruit juice-based products. Based on the analysis of thin-layer chromatography (TLC), a majority of fruit nectar samples (57.14%) contained natural colorants, while 42.86% of total samples contained synthetic colorants. Labelling violation was done by the manufacturers, and the consumer awareness was high with the color-coding system. Continuous surveillance is recommended to minimize health risk related to high sugar consumption of the population.

No abstract

The effect of thermal processing on health-promoting phytochemicals was investigated in relation to the canning of mango and pineapple. The cans were retorted at four different temperatures for varying amounts of time. Vitamin C, β-carotene, polyphenols, flavonoid content, and antioxidant capacity in canned fruit pieces and sugar syrup were determined. The diffusion and leaching of phytochemicals were determined through mathematical modelling. Retention of vitamin C in canned pineapple pieces was higher than in canned mango pieces. Thermal treatment had an effect of rapidly reducing leached vitamin C. The activation energy required for the degradation of vitamin C and β-carotene in mango was higher than that required in pineapple. Trolox equivalent antioxidant capacity (TEAC) values at 130 °C (40 min) were 3.1 and 1.9 μmol Trolox/g FW in mango pieces and syrups, respectively, indicating that antioxidant leaching had occurred. The degradation constants of the phytochemicals studied were comparable but were slightly higher in pineapple than in mango. The investigated health-promoting phytochemicals in canned products were present in substantially lower concentrations than in fresh mango and pineapple.

No abstract

No abstract

The research was conducted to investigate the potential of incorporation of Olu (white water lily or hairy water lily), Nymphaea pubescens Willd seeds flour with wheat flour in cookies and evaluation of their organoleptic properties. The proximate composition of Olu seed samples was determined. The control (wheat flour) and six cookie formulations replacing wheat flour with white water lily seed flour (20, 30, 40, 60, 80 & 100%) were prepared. The organoleptic attributes; colour, odour, taste, texture, sweetness and overall acceptability were evaluated on a Hedonic scale (7-points) using an untrained panel. Proximate composition of Olu seeds included moisture 12.04 ± 0.06%, ash 0.54 ± 0.04%, fat 0.46 ± 0.05%, crude protein 2.35 ± 0.04%, crude fibre 0.58 ± 0.05% and carbohydrates 84.03 + 06%. The results showed that except for odour and texture, all the other sensory attributes of 30% substitution were scored as like slightly (5) or sometimes more acceptable than the control. However, the cookies with 40% and higher than 40% olu seed flour formulations were less acceptable than 30% formulation in all sensory attributes. According to the Friedman test, there was a significant difference of cookies in terms of colour, taste, sweetness and overall acceptability (p = 0.05).