Nutritional analysis of selected wild edible vegetables of the Vhembe region, South Africa

For rural communities, wild edible plants play a paramount role as foods, which improve their nutritional livelihood and combat food insecurity. The prevalence of Vitamin A, Vitamin C, Fe, and Zn from eight wild edible vegetables were studied. The micronutrients have the highest deficiency prevalence in human in the Vhembe region of the Limpopo Province, South Africa whereas trace elements studied in this research play indispensable roles in the maintenance of health and disease states of humans and domestic animals. Plant samples (leaves), free of infections, were obtained from street hawkers located between Levubu and Makhado in the province. Analysis of Fe, Zn, b-carotene and quantification of Vitamin C was achieved by following methods which are explained in the methodology section with slight modifications. Amaranthus Hybridus L. contained high amounts of 226±3.06 mg/100g and 15.5+/-3.52 mg/100g of Fe and Zn respectively. Solanum retroflexum was found to have the highest amount of Vitamin A (b-carotene) of 10.91 mg/100g DW , while Amaranthus thunbergii contained the highest (69.11mg/100g DW) amount of Vitamin C. There is a chance of blending wild edible vegetables for consumption. The blending of Solanum retroflexum and Amaranthus thunbergii is therefore recommended as it promotes Vitamin A and Vitamin C contents in the diet of humans.

SOLANUM EMULANS RAF. AND SOLANUM SCABRUM MILL. (SOLANACEAE) IN THE UDMURT REPUBLIC

Information about the finds in the Udmurt Republic of two adventive Solanum species is reported. Of these, Solanum emulans is a new species for the flora of Russia. It is brought to the city of Izhevsk with North American grain. In 1993, three of its locations were discovered: at the Izhevsk railway station and in the wastelands in the courtyards of the Izhevsk bakery plant and the Izhevsk bread-receiving enterprise no. 2. Solanum scabrum is occasionally cultivated by amateur gardeners as an exotic plant. In a wild state, it has been known since 2000. To date, eleven of its locations are known in the cities of Izhevsk, Votkinsk, Mozhga, Sarapul, as well as in Zavyalovsky, Uvinsky, Yakshur-Bodinsky and Yarsky districts. Most of its finds are associated with dumps and municipal waste dumping sites. In the conditions of the Udmurt Republic, Solanum emulans and Solanum scabrum are ephemerophytes. The features that distinguish Solanum emulans and Solanum scabrum from morphologically similar species such as Solanum americanum, Solanum nigrum., Solanum retroflexum are given.

Solanum retroflexum в Приморском крае

Впервые в дальневосточном регионе рассмотрен малораспространенный в РФ паслен Solanum retroflexum, который ценится в качестве источника антиоксидантов. Изучена рассадная технология возделывания вида в Приморском крае. Посев — 18 – 20 апреля, семена сохраняют высокую всхожесть минимум в течение 3 лет. Высадка рассады в открытый грунт — 10 – 12 июня по схеме 45 × 50 см. В течение вегетационного периода растения остаются без видимых повреждений вредителями и поражений болезнями. Сбор ягод возможно производить в 1 прием 18 – 22 сентября или в 2 приема: в конце августа (75 % ягод) и остальное — 18 – 22 сентября. Плоды не осыпаются, без растрескиваний хорошо сохраняются на корню, несмотря на сильное переувлажнение в августе – сентябре, характерное для условий Приморского края. По результатам учетов 2 лет получен урожай 1000 – 1200 г/м2 ягоды, что соответствует в среднем 219 плодам массой 243 – 292 г с 1 растения. Для улучшения вкусовых качеств продуктов переработки паслена рекомендуется приготовление варенья в ассорти с ягодами других дальневосточных культур, созревающих осенью. Интродуцированному в Россию культурному виду Solanum retroflexum требуются номенклатурные уточнения.

Deciphering the effects of kosmotrope and chaotrope salts during aqueous two phase extraction (ATPE) of polyphenolic compounds and glycoalkaloids from the leaves of a nutraceutical plant, Solanum retroflexum, with the aid of UPLC-QTOF-MS

Solanum plants (Solanaceae) are renowned source of nutraceuticals and have widely been explored for their phytochemical constituents. This work investigated the effects of kosmotropic and chaotropic salts on the number of phytochemicals extracted from the leaves of a nutraceutical plant, Solanum retroflexum, and analyzed on the ultra-performance liquid chromatography hyphenated to a quadrupole time of flight mass spectrometer (UPLC-QTOF-MS) detector. Here, a total of 20 different compounds were putatively characterized. The majority of the identified compounds were polyphenols and glycoalkaloids. Another compound, caffeoyl malate was identified for the first time in this plant. Glycoalkaloids such as solanelagnin, solamargine, solasonine, β-solanine (I) and β-solanine (II) were found to be extracted by almost all the salts used herein. Kosmotrope salts, overall, were more efficient in extracting polar compounds with 4 more polyphenolic compounds extracted compared to the chaotropes. Chaotropes were generally more selective for the extraction of less polar compounds (glycoalkaloids) with 3 more extracted than the kosmotropes. The chaotrope and the kosmotrope that extracted the most metabolites were NaCl and Na2SO4, respectively, with 12 metabolites extracted for each salt. This work demonstrated that a comprehensive metabolome of S. retroflexum, more than what was previously reported on the same plant, can be achieved by application of kosmotropes and chaotropes as extractants with the aid of the Aqueous Two Phase Extraction approach. The best-performing salts, Na2SO4 or NaCl, could potentially be applied on a commercial scale, to meet the ever-growing demand of the studied metabolites. The Aqueous Two Phase Extraction technique was found to be efficient in simultaneous extraction of multiple metabolites which can be applied in metabolomics.

Effects of Different Drying Methods on Untargeted Phenolic Metabolites, and Antioxidant Activity in Chinese Cabbage (Brassica rapa L. subsp. chinensis) and Nightshade (Solanum retroflexum Dun.)

Chinese cabbage (Brassica rapa L. subsp. chinensis) and Nightshade (Solanum retroflexum are popular traditional leafy vegetables consumed predominantly by rural Africans. Sun drying is adopted as a traditional method of postharvest preservation to store theses leaves during off seasons. The influence of different types of postharvest processing treatments, such as conventional oven drying, solar cabinet drying, sun drying and freeze drying, on the changes on colour properties and antioxidant components were investigated. Freeze-drying retained the ascorbic acid content, antioxidant activities, total chlorophyll content, green colour by reducing the colour difference (∆E). With regard to Chinese cabbage and Nightshade leaves, sun and microwave drying respectively had the most negative impact on all the identified phenolic compounds. The OPLS-DA and the UPLC–QTOF/MS and chemometric approach showed kaempferol-3-O-sophoroside, kaempferol-3-sophorotrioside-7-glucoside and hydroxyoctadecenedioic acid as the markers responsible for the separation of sun-dried samples from the other drying treatments in Chinese cabbage. Sinapoyl malate was not detected in sun-dried samples. Caffeoylmalic acid was identified as the marker compound to separate the other drying treatments from the microwave dried samples of Nightshade leaves. Trihydroxyoctadecadiene derivative and hydroxyoctadecanedioic acid were detected in microwaved samples. Due to the cost effectiveness, solar dryer cabinet treatment was recommended for drying both vegetables. The proximate analysis of solar dried functional powder of Chinese cabbage and Nightshade vegetables demonstrated higher contents of protein and dietary fibre.

Phytochemical Composition of Solanum retroflexum Analysed with the Aid of Ultra-Performance Liquid Chromatography Hyphenated to Quadrupole-Time-of-Flight Mass Spectrometry (UPLC-qTOF-MS)

Solanum retroflexum (nightshade) is an edible plant that is consumed in some regions of South Africa. Its leaves are a good source of vitamins, proteins, and minerals. It appears that there is no scientific report about the phytochemical composition of S. retroflexum. Here, ultra-performance liquid chromatography coupled to quadruple-time-of-flight mass spectrometry (UPLC-qTOF-MS) technique was use to achieve an untargeted metabolite fingerprinting of this plant. A total of 30 phytochemicals, including alkaloids, flavonoids, and cinnamic acids derivatives, were identified from the methanolic leaf extracts. The concentration of solvent did not affect the type of compounds extracted. The extraction resulted in qualitative yields of molecules such as quercetin-3-rutinoside, kaempferol-3-0-rutinoside, kaempferol-3-0-glucoside, 3-caffeoylquinic acid, 5-caffeoylquinic acid, and 3, 4-di-caffeoylquinic acid. The present study confirms the presence of phytochemical compounds in S. retroflexum similar to other Solanum plants.