African indigenous vegetables (AIVs) because of their nutrient density have the unique potential to reduce micronutrient deficiencies in sub-Saharan Africa, yet some may also contain anti-nutritive compounds. Vegetable nightshades from Solanum americanum, Solanum nigrum, Solanum scabrum and Solanum villosum are among the major AIVs used as a leafy vegetables and consumed regularly in many countries in sub-Sahara Africa. These under-recognized food crops have not been subjected to extensive studies for their nutritional and antinutritive factors. In this study, 15 entries of the vegetable nightshades were field-grown and the leaves which are the consumed product of commerce chemically profiled by LC/ESI-MS. Twenty-three flavones, eight saponins, and two glycoalkaloids along with a phenolic acid of chlorogenic acid were identified by MS and UV data. Anti-nutrient glycoalkaloids were quantified as total aglycones after acidic hydrolysis using MS detection and found to be within safe-consumption thresholds by comparison with the glycoalkaloid level in the globally consumed Solanum member eggplants. Edible nightshades were also found to be sources of β-carotene, vitamin E and total polyphenols and exhibited high antioxidant activity. Results of this study support that consumption of vegetable nightshades are safe from the presence of glycoalkaloids and thus, can contribute to the reduction of micronutrient deficiency in sub-Sahara Africa.

Consumption safety of Solanum scabrum berries is controversial in different cultural practices and evaluation of the toxicity as well as micronutrition value relies on relevant phytochemical study. Thus, this study aimed to systematically profile the phytochemicals in the berries from different genetic sources and maturity. Using a combination of three different and complementary methods of HPLC-UV/Vis-MS or MS/MS with acid-assisted hydrolysis, a total of 54 phytochemicals were identified including polyphenols, saponins and toxic glycoalkaloids. Particularly, a broad range of glycoalkaloids of solasodine and its uncommon or potentially novel hydroxylated and methylated derivatives were reported, with the structure putatively identified based on the known scaffold-fragmentation pattern. Other identified phytochemicals included phenolic acids of chlorogenic acid and neochlorogenic acid, flavonol glycosides of quercetin and isorhamnetin, anthocyanins of petunidin, malvidin and delphinidin, and saponins of diosgenin and tigogenin. Practical Application:This study provides solutions for identifying the phytochemicals of S. scabrum berries, and unveiled for the first time a wide range of toxic glycoalkaloids of solasodine and analogues in the berries from different genetic sources and maturation stages. This work laid the foundation for prospective quantitative determination of berry phytochemicals and future toxicity and nutrition evaluation, and could also apply to facilitate screening or breeding for glycoalkaloid-deficient genotypes that can be used as new food supply.

The rapid expansion of Asian populations in the United States presents significant opportunities and challenges for the eastern U.S. produce sector to take advantage of their close proximity to densely populated areas. Initial crop studies followed by ethnic consumer and crop surveys were conducted to examine vegetable, leafy green, and herb consumption and expenditures among Chinese, Asian Indians, and other Asian groups. Consumer choices were used to prioritize subsequent production trials. Family expenditures were determined for specific Asian produce types and total produce purchases. This market data were extrapolated to the east coast Asian populations to assess potential market size (90% confidence interval, error margin 5.6%). Chinese consumer values ranged from $245 to $296 million per annum and Asian Indians ranged from $190 to $230 million per annum. The average annual fresh fruit and vegetable expenditures by both Asian groups were 2 to 3.5 times respective national averages. Leading Chinese vegetables determined by average expenditures were baby bok choy, pak choy, oriental eggplant, snow pea, oriental spinach, and napa cabbage. Highest expenditure of leafy greens and herbs for Chinese consumers were chives and garland chrysanthemum. This market-driven survey reported consumption of over 100 Asian crops and 42 cultivars were ranked “feasible” to grow in the eastern section of the United States. Horticultural matrices of selection criteria narrowed the list to the most promising candidates for production. As a result, 28 cultivars were then grown in University research and demonstration plots at Massachusetts, New Jersey, and Florida in determining growth characteristics and yield to focus horticultural crop producers. Leading vegetable cultivars for Asian Indian consumers were bitter gourd, eggplant, fenugreek leaves, cluster beans, and bottle gourd. Leading leafy greens and herbs for Asian Indians were turmeric, fenugreek, sorrel spinach, and radish greens. Most of these Asian cultivars were demonstrated to grow well in the three main growing zones of 5, 7, and 9. Phytochemical attributes such as antioxidant activity, polyphenols, and mineral contents were analyzed for several of the leading crop candidates. This initial field and laboratory data shows that many of these ethnic crops can be grown in the eastern United States to direct production opportunities and are nutrient rich to help drive consumer demand.

BACKGROUND Solanum scabrum berries in sub‐Saharan Africa are prolific but neglected as an agricultural resource. Recognition and application of such underutilized resources rely on systematic study of the relevant phytochemicals of commercial value. RESULTS The quantities of a total of 54 phytochemicals in Solanum scabrum berries were assessed using HPLC‐MS methods. Berries from eight different genetic sources were analyzed with two entries monitored across different maturation stages. There was a significant variation among mature berries in the accumulation of phenolic acids, 91.5–794 mg·100 g−1 dry weight (DW); flavonols, 76.3–897 mg·100 g−1 DW; anthocyanins, 178–4650 mg·100 g−1 DW; glycoalkaloids, 1.76–1630 mg·100 g−1 DW; and saponins, 82.2–606 mg·100 g−1 DW. Fruit development from immature to post‐frost harvest featured dynamic changes in phytochemical composition and, despite remarkable differences in the absolute magnitude of content, the trend of change was generally similar in different genetic sources. CONCLUSIONS The genotype‐dependent difference in toxic glycoalkaloids in mature berries may partially explain the consumption controversy as it reflects glycoalkaloid content. The analytical methods applied in this work should serve for quality control of glycoalkaloids thereby improving the safe utilization of this berry. In addition, the selection and breeding of new genotypes with low and safe levels of glycoalkaloids and saponins in the berry could be of value in sub‐Saharan Africa to increase nutrition and generate new income opportunities for growers. © 2019 Society of Chemical Industry

No abstract