The study evaluated the effects of six pretreatment methods before cooking on the peroxidase activity, chlorophyll and antioxidant profile of Amaranthus cruentus L. and Solanum nigrum L. The six pretreatments methods used were chopped only (raw sample) (coded M1); chopped and dried at 50°C for 5 h (coded M2); chopped and squeezed in water (at room temperature) (coded M3); chopped and soaked in warm water (approximately 60°C), then cooled and squeezed (coded M4); chopped and soaked in salt-treated water (approximately 20 g NaCl per litre of water) for 15 min, then squeezed (coded M5) and chopped and soaked in boiling water (100°C), then cooled and squeezed (coded M6). The main effect of vegetable type and the main effect of pretreatment methods have significant effects (P 6 0.05) on the parameters measured, while the interaction of vegetable type and pretreatment methods have no significant effect on the parameters measured. Statistical analyses (P 6 0.05) showed that chlorophyll a and b occur in ratio 3:1 in the two vegetables, irrespective of the pretreatment imposed. Peroxidase activity test showed that A. cruentus, irrespective of the pretreatment imposed showed, no peroxidase activity, while S. nigrum showed high peroxidase activity for all the pretreatments except for M6. Results showed that there was a significantly (P 6 0.05) higher content of carotenoids in A. cruentus when compared with S. nigrum, while the total phenolics, total flavonoids and total tannins contents were higher in S. nigrum when compared with A. cruentus, irrespective of the pretreatment method used. For the two vegetables, the percentage losses in total carotenoids, phenolics, flavonoids and total tannins at M6 when compared with M1 were 53.3-60.5%, 55.6-57.1%, 62.4-63.6% and 66.1-73.5%, respectively. There was a sharp drop in the carotenoids, phenolics, flavonoids and tannins contents of the two vegetables at M4 and M6, with both treatments having closely similar values for each parameter.

The study investigated the effect of supplementation of the leaf powders of Telfairia occidentalis, Amaranthus viridis, and Solanum macrocarpon on the chemical composition and the quality characteristics of wheat bread. The bread samples were supplemented with each of the vegetable leaf powders at 1%, 2%, and 3% during preparation. The bread samples were assayed for proximate composition, mineral composition, physical, sensory, and antioxidant properties using standard methods. The addition of vegetable powders significantly increased the protein (9.50 to 13.93%), fibre (1.81 to 4.00%), ash (1.05 to 2.38%), and fat (1.27 to 2.00%). Supplementation with vegetable powder however significantly decreased ( < 0.05) the carbohydrate and moisture contents. Significant ( < 0.05) increases were recorded for all evaluated minerals as the level of vegetable powder increased. Supplementation with vegetable powder caused significant decrease in total phenolic content, percentage DPPH inhibition, metal chelating ability, ferric reducing antioxidant power, and total antioxidant capacity. Sensory results showed that there was significant decrease in sensory qualities with increasing supplementation. This therefore suggests that bread supplemented with vegetable powder could have more market penetration if awareness is highly created.

The phyto-constituents and antioxidant activity of the fruit pulp of Trichosanthes cucumerina L. have not been reported in literature and were therefore studied. Two identified morphotypes of this plant (Morphotype I [V1] having long fruit with deep green background and white stripes; and Morphotype II [V2] having light green coloured long fruit) were used for the studies. The dry matter contents of the pulp of the V1 and V2 were 10.9 and 9.6 g/100 g fresh weight (FW), while the ascorbic acid contents were 25.7 and 24.8 mg/100 g fresh weight (FW), and lycopene contents were 18.0 and 16.1 mg/100 g FW, respectively. The total phenolics, total flavonoids and total ferric reducing antioxidant power (FRAP) of V2 were significantly higher (P< 0.05) than that of V1 by 46.8%, 78.0% and 26.2%, respectively. Bulk of the carotenoids is made up of lutein in the concentration of 15.6 and 18.4 mg/100 g FW, for V1 and V2, respectively. The alpha-carotene contents were 10.3 and 10.7 mg/100 g FW while the beta-carotene contents were 2.4 and 2.8 mg/100 g FW for V1 and V2, respectively. It is concluded from the results of this study that the two morphotypes of T. cucumerina possess valuable nutraceutical properties that can qualify them as viable substitute to the Solanaceous tomato.

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This article is focused on the global trend in research with special emphasis on the economic importance of polyphenols. We examined some of the media used for the formulation of polyphenol-enriched products. The levels of polyphenol extract production, international research funding, and number of published research work were determined from various databases and publicly available reports. The quantity of industrially extracted polyphenols was estimated to be 16,380 tons in 2015 and this is anticipated to reach a total of 33,880 tons by the end of 2024 with an estimated monetary value of USD 1.33 billion. Industrial utilization of polyphenol is dominated by the functional beverages sector (44%), followed by functional foods (33%) primarily due to high demands for polyphenol-rich consumables. Within a 10-year period, the number of polyphenol-related publications doubled from 2006 (1,574) to 2012 (3,330) and almost tripled in 2015 (4,213). Practical applicationsPolyphenols remain one of the most researched bioactive food compounds because of their wide distribution in nature and also due to their versatility as agents that can improve human health and enhance the shelf-life of foods. This report combines available scientific knowledge on the various factors that dictate polyphenol synthesis in plants, extraction methods, and utilization. The report also provides information on global polyphenol research and project funding history, which could serve as a critical reference for researchers all over the world. K E Y W O R D S functional foods, health benefits, polyphenols, research funding, solvent extraction, vegetables