Screening of traditional South African leafy vegetables for specific anti-nutritional factors before and after processing

ESSACK, Humaira; Odhav, Bharti; Mellem, John J.

doi:10.1590/1678-457x.20416

Cited by 52 publications

(64 citation statements)

References 21 publications

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“…A study by Virginia et al (2012) on effects of cooking and processing on oxalate content in green leafy vegetables and pulses revealed that blanching, pressure cooking for 10 min and open pan cooking of green leafy vegetables reduced their oxalate concentration from 88.8 mg/100 g fresh samples to 48.4, 57.2 and 60.13 mg/100 g, respectively. Other studies reported reduction of oxalates in boiling and drying of vegetables (Essack et al, 2017;Ilelaboye et al, 2013;Mwanri et al, 2011); which means the amount of oxalate present in studied vegetables may not be harmful for human consumption since the contents were relatively low and these vegetables are usually boiled before consumption.…”

Section: Discussionmentioning

confidence: 84%

Oxalate, phytate and nitrate content in African nightshade, spider plant and amaranths at different stages of maturity

Mwanri¹,

Mamboleo²,

Msuya³

et al. 2018

Afr. J. Food Sci.

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African indigenous green leafy vegetables play important role in income generation and subsistence; they are the cheapest and most readily available sources of important minerals and vitamins. On the other hand, they contain anti-nutritional factors that reduce availability of vital nutrients. This study was conducted to determine oxalates, phytates and nitrates content in commonly consumed Amaranths cruentus, Spider plant (Cleome gynandra) and African night shade (Solanum villosum) at 21, 28 and 35 days age of the plant harvest. Vegetables were planted on plots and harvested at 21, 28 and 35 days. At each stage, about 600±2 g of the edible part was harvested and standard chemical analyses procedures were followed to determine oxalate, phytate and nitrate contents. Using Statistical Product and Service Solutions (SPSS 20) data were analysed and results presented as simple means, ranges and standard deviations. Analysis of variance (ANOVA) with 5% level of significance was done to determine differences in the levels of nutrients between the vegetable varieties and three maturity stages. African nightshade Nduruma BG 16 had lowest oxalate concentrations (28.7  0.1 mg/100 g) at maturity stage I while African nightshade Olevolosi SS 49 had the highest value (60.9  0.9 mg/100 g) at maturity stage III. There was no particular trend for phytates in all maturity stages and in all varieties but amaranths Madiira AM 38 had exceptionally the highest values (0.7  0.0 mg/100 g) at stage III of maturity. The highest nitrate content was 85.6  1.8 mg/100 g in Olevolosi SS 49 at maturity stage I, whereas the lowest value was 45.3  1.3 mg/100 g in amaranths Madiira AM 38 at stage III. There was a slight variation in antinutrients composition of the studied vegetables and the composition was generally very low.

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Section: Discussionmentioning

confidence: 84%

Oxalate, phytate and nitrate content in African nightshade, spider plant and amaranths at different stages of maturity

Mwanri¹,

Mamboleo²,

Msuya³

et al. 2018

Afr. J. Food Sci.

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“…Food processing may affect the functionality and nutritional quality of the food products [34]. Also, it leads to beneficial transformations, compound degradation, or nutrient loss [35]. The effect of boiling on proximate composition of Solanum nigrum leaves is given in Table 1.…”

Section: Discussionmentioning

confidence: 99%

Effect of Boiling on Chemicals, Phytochemicals and Nutritional Composition of Solanum nigrum L. Leaves Harvested in Abidjan (Côte d’Ivoire)

Dappah

N’Dri

Kouassic

et al. 2020

IJBcRR

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Aims: In tropical Africa, leafy vegetables are traditionally cooked and eaten as a relish together with a starchy staple food. The current study aimed to evaluate the influence of boiling on bioactive, proximate and antinutrients compounds in Solanum nigrum leaves. Methodology: The leaves were subjected to boiling in pressure cooker for 10, 15 and 20 min and proximate composition, minerals, nutritive and anti-nutritional components were determined according to standard methods for nutritional guidelines. Results: The result of the study revealed that longer time of boiling (higher than 10 min) caused negative impact by reducing nutritive value but positive impact by reducing anti-nutrients. The registered losses (p < .05) at 10 min were as follows: ash (12.37%), proteins (33.69%), vitamin C (11.23 mg/ 100 g), polyphenols (125.41 mg/ 100 g) Tannins (81.96 mg/ 100 g) and Flavonoids (14.03 mg/100 g). The average increase of fibers content was (39.41%). Furthermore, after 10 min of boiling time the residual contents (p<0.05) of minerals was: Calcium (1079±29.04 to 386±78 mg/ 100 g), Phosphorus (405..24±10-508.88±2.58 mg/ 100 g), Iron (33.48±0.93–44.50±1.23 mg / 100 g) and Magnesium (572.78±19.76–662.99±27.23 mg/ 100 g).The antinutrient composition for oxalic acid were ranged 72.61±6.29 to 223.67±6.35 mg/100 g. The different ratios sodium / potassium (<1) and oxalates/calcium (<2.5) were under the respective critical value for all boiling. Conclusion: These results suggest that the recommended time of domestic cooking must be less than 10 min for the studied leafy vegetables in order to contribute efficiently to the nutritional requirement and to the food security of Ivorian population.

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“…Leunca termasuk sedikit di antara anggota Solanaceae yang dimanfaatkan bagian daun dan buah sekaligus dan yang lebih banyak dikonsumsi adalah buah atau umbinya seperti cabe, terong, tomat, dan kentang. Daun atau pucuk S. nigrum mengandung glikosida atau nitrat dalam jumlah tinggi (Masinde et al 2007;Essack et al 2017). Sudah diketahui bahwa kandungan glikosida dan nitrat dipengaruhi oleh nitrogen (Bvenura & Afolayan 2014;Putriantari & Santosa 2014;Janet et al 2016;Ou et al 2017;Sabu & Kalpana 2017).…”

Section: Pendahuluanunclassified

Shoots and Fruits Harvesting of Solanum nigrum L. Treated with Different Nitrogen Levels

Yulianti

Santosa²,

Susila

2020

JIPI

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ABSTRAKPeningkatan popularitas pucuk dan buah leunca sebagai sayuran di Indonesia mendorong petani memanen keduanya secara bergantian pada tanaman yang sama dan tingkat hasil diduga dipengaruhi oleh dosis pupuk, khususnya nitrogen. Penelitian ini bertujuan untuk mengetahui dosis pupuk nitrogen terbaik pada tanaman leunca yang dipanen pucuk dan buah dalam satu tanaman. Bibit leunca ditanam di Kebun Percobaan Leuwikopo IPB dengan lima dosis N, yakni 0, 90, 180, 270, dan 360 kg/ha. Hasil menunjukkan bahwa panen pucuk dan buah leunca sensitif terhadap dosis nitrogen. Pada dosis N rendah, hasil panen buah lebih tinggi dibandingkan dengan panen daun, sedangkan pada dosis N tinggi hasil panen daun lebih tinggi dibandingkan dengan hasil panen buah. Hubungan panen daun dan buah dengan dosis N menunjukkan pola kuadratik, yakni r 2 =0,9671 dan r 2 =0,9483 dengan dosis N optimum untuk produksi daun sebesar 304,8 kg/ha dan produksi buah sebesar 336,5 kg/ha. Ketepatan dosis N pada tanaman leunca penting karena status kandungan nitrat daun mengikuti pola positif kuadratik (r 2 =0,5264) dan linear pada buah (r 2 =0,9587) dengan peningkatan dosis dari sebesar 90 menjadi 360 kg N/ha. Dari nilai akumulasi bobot total panen pucuk (3 kali panen) dan buah (4 kali panen), dosis N terbaik panen pucuk dan buah leunca dapat dilakukan pada tanaman yang sama sebesar 271,1 kg/ha (r 2 =0,9644). Kata kunci: laju fotosintesis, ranti, serapan N, status nitrat, tumpang sari ABSTRACT The increasing popularity of leaf and fruit of African nightshade as vegetables in Indonesia stimulates farmers to harvest both leaf and fruit from single plant alternately; the yield is presumably affected by fertilizer rate, e.g., nitrogen. The present study aimed to evaluate such hypothesis through evaluation of plant production, N absorption, and its status. Seedlings were treated with five N levels, i.e., 0, 90, 180, 270, and 360 kg/ha in Leuwikopo Experimental Farm, IPB Bogor, Indonesia. The results revealed that leaf and fruit productions were sensitive to nitrogen level. Leaf and fruit productions had quadratic correlation to N levels, i.e., r 2 =0.9671 and r 2 =0.9483 with optimum dosages as 304.8 kg/ha and 336.5 kg/ha, respectively. Proper N application is important for both leaf and fruit productions because nitrate level in leaf had quadratic relationship (r 2 =0.5264) and it has a linear relationship in fruit production (r 2 =0.9587) by increasing N level from 90 to 360 kg N/ha. From the total fresh mass leaves and fruits harvested, the optimum N for the best alternate harvesting was 271.1 kg/ha (r 2 =0.9644).

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Screening of traditional South African leafy vegetables for specific anti-nutritional factors before and after processing

Cited by 52 publications

References 21 publications

Oxalate, phytate and nitrate content in African nightshade, spider plant and amaranths at different stages of maturity

Oxalate, phytate and nitrate content in African nightshade, spider plant and amaranths at different stages of maturity

Effect of Boiling on Chemicals, Phytochemicals and Nutritional Composition of Solanum nigrum L. Leaves Harvested in Abidjan (Côte d’Ivoire)

Shoots and Fruits Harvesting of Solanum nigrum L. Treated with Different Nitrogen Levels

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