Optimum Harvest Time of Cucumis africanus Fruit Using Concentration of Cucurbitacin B as a Maturity Standard

Shadung, K. G.; Mashela, P. W.; Mulaudzi, Vusimuzi; Mphosi, M. S.; Ncube, Ignatious

doi:10.5539/jas.v7n10p181

Cited by 3 publications

(3 citation statements)

References 23 publications

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“…EXPERIMENTAL DESIGN AND TREATMENTS. Sixty fruit from each plot were harvested at fruit maturity (Shadung et al, 2015), chopped into pieces, and divided equally into six portions. Each portion per plot was randomly assigned to one of the six forced-air drying ovens (EcoTherm; Labotech, Cape Town, South Africa).…”

Section: Study Site and Raising Wildmentioning

confidence: 99%

Suitable Drying Temperature for Preserving Cucurbitacins in Fruit of Wild Cucumber and Wild Watermelon

Shadung

Mashela

Mphosi

2016

hortte

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The thermostable cucurbitacin A and B from mature fruit of wild cucumber (Cucumis myriocarpus) and wild watermelon (Cucumis africanus), respectively, are used in product development for various industries. Mature fruit from wild cucumber and wild watermelon suffer from high incidents of postharvest decays. Drying fruit at the recommended temperatures of 30 to 40 °C for medicinal plants resulted in molds developing on the material, with optimum temperature to prevent decays being at 52 °C. The influence of 52 °C and higher temperatures on active ingredients in the two fruit had not been documented. The objective of this study, therefore, was to determine the relative effects of increasing drying temperatures above the 52 °C standard on concentrations of cucurbitacin A and B in fruit of wild cucumber and wild watermelon. Fruit pieces were oven-dried at 52, 60, 70, 80, 90, and 100 °C for 72 hours. Relative to 52 °C, higher temperatures resulted in 25% to 92% less cucurbitacin compared with the maximum produced at 60 °C. In contrast, relative to 52 °C, higher temperatures reduced concentrations of cucurbitacin B by 47% to 86%. In conclusion, the compromise temperature of 52 °C for preserving fruit pieces in wild cucumber and wild watermelon from decay should also be viewed as the optimum temperature for preserving cucurbitacin A and B.

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Section: Study Site and Raising Wildmentioning

confidence: 99%

Suitable Drying Temperature for Preserving Cucurbitacins in Fruit of Wild Cucumber and Wild Watermelon

Shadung

Mashela

Mphosi

2016

hortte

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“…Cucumis myriocarpus and C. africanus plants were cultivated in separate fields, with mature fruits harvested at 92 days after transplanting [19] Fruits were washed using chlorine-free tapwater, cut into pieces and dried at 52˚C for 72 h. Separate sets of fruit pieces for each Cucumis species were dried at 100˚C for 72 h to observe if high temperatures would be detrimental to the product as found previously under unfixed conditions [13]. Dried materials were separately ground in a Wiley Mill Model 4 to pass through a 1-mm-pore sieve.…”

Section: Preparation Of Phytonematicidesmentioning

confidence: 99%

Shelf-life in cucurbitacin-containing phytonematicides: Non-conformity to Arrhenius model

Mashela¹,

Shokoohi²,

Pofu³

2020

PLoS ONE

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Shelf-life information provides end-users with the assurance that the product is still in compliance with label claims. Behavioral reaction orders of the Arrhenius model had been consistently used under fixed conditions to provide shelf-life in food products. Due to nonconformity of the cucurbitacin-containing phytonematicides to the Arrhenius behavioral reaction orders, an alternative quadratic model consistent with the behavioral reaction orders of cucurbitacins was developed under chilled (5˚C at 95-98% RH) and fixed tropical (38˚C at 90% RH) conditions, while room temperature constituted unfixed conditions. Sampling for cucurbitacins was done at time-frames compliant with geometric series, with cucurbitacin analysis regularly performed using high-performance liquid chromatography techniques. Under chilled conditions, neither the Arrhenius nor the quadratic model could predict the shelf-life for Nemarioc-AL phytonematicide, whereas Nemafric-BL phytonematicide had shelf-life of 35 weeks. In contrast, under tropical conditions, the positive quadratic models showed that Nemarioc-AL and Nemafric-BL phytonematicides had shelf-life of 35 and 825 weeks, respectively. In conclusion, the two phytonematicides could be stored under fixed tropical conditions to enhance the shelf-life of their active ingredients.

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“…Fruits of the two Cucumis species were collected from cultivated fields, separately cut into pieces, dried at 52°C and milled in a Wiley mill as previously described (Shadung et al, 2015). The products were prepared using standard fermentation procedures .…”

Section: Plant Materials and Cultural Practicesmentioning

confidence: 99%

Study of chemical residues from Nemarioc-AL and Nemafric-BL phytonematicides in tomato fruit

Shadung¹,

Mashela²,

Mphosi³

et al. 2017

Afr. J. Agric. Res.

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Pesticide chemical residues in produce and products are a global concern in human and animal diets. Nemarioc-AL (a.i. cucurbitacin A) and Nemafric-BL (a.i. cucurbitacin B) phytonematicides serve as alternatives to synthetic nematicides in the management of root-knot nematodes (Meloidogyne spp.) in tomato (Solanum lycorpersicum) production. Cucurbitacins are the bitterest chemical compounds, and therefore, could affect fruit taste when used in tomato production to manage nematodes. The objective of this study was to determine whether tomato fruit where nematode numbers were managed using the two phytonematicides, contain cucurbitacin chemical residues. A field study using tomato cv. 'Rodade' was initiated, with untreated control, Nemarioc-AL and Nemafric-BL phytonematicides, laid out in randomised complete block design, with thirteen replications. Each phytonematicide at 3% was applied at a 17-day interval. At 110 days, after initiating the treatments, fruit were sampled and analysed for chemical residues using the isocratic elution Shimadzu HPLC Prominence with Shimadzu CTO-20A diode array detector. Cucurbitacin A and B residues were not detected in 'Rodade' fruit and therefore, the two phytonematicides were suitable for nematode management in tomato production under field conditions.

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Optimum Harvest Time of Cucumis africanus Fruit Using Concentration of Cucurbitacin B as a Maturity Standard

Cited by 3 publications

References 23 publications

Suitable Drying Temperature for Preserving Cucurbitacins in Fruit of Wild Cucumber and Wild Watermelon

Suitable Drying Temperature for Preserving Cucurbitacins in Fruit of Wild Cucumber and Wild Watermelon

Shelf-life in cucurbitacin-containing phytonematicides: Non-conformity to Arrhenius model

Study of chemical residues from Nemarioc-AL and Nemafric-BL phytonematicides in tomato fruit

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