Effect of Cooking Methods on Ascorbic Acid Destruction of Green Leafy Vegetables

Ascorbic acid is highly sensitive vitamin to various modes of cooking processes. Ethiopian green collards (Brassica carinata), locally called Ye’abesha Gomen, and cabbage (Brassica oleracea) are important green vegetables for ascorbic acid source in the country. The rate of ascorbic acid degradation in cabbage and Ethiopian green collard was studied employing two processing methods: open-pan and pressure cooking which are highly customized in household cooking. Samples were cooked at 5, 10, 15, 20, 25, 30, and 35 min under each processing method. Ascorbic acid concentration in each sample was determined by using a spectrophotometer at 520 nm wavelength using the standard plot of pure ascorbic acid solution. The initial concentration of ascorbic acid in fresh cabbage and Ethiopian green collard were found to be 33.76 ± 0.58 and 38.14 ± 0.19 mg/100 g, respectively. Well-cooked and edible Ethiopian green collard was obtained at 10 minutes of cooking time by pressure cooking with ascorbic acid retention of 31.8% from its initial contents. However, a cooking time of 25 min was required by the open-pan cooking method with 26.8% ascorbic acid retention. Edible cabbage was attained at 10 and 20 minutes of cooking time by pressure and open-pan cooking methods maintaining 36.9 and 30.9% of ascorbic acid, respectively. Thus, the pressure cooking method required short cooking time for having well-cooked and edible green leafy vegetable with better ascorbic acid retention. The outputs of this work would be helpful to design and control practical thermal processing situations and to minimize the loss of ascorbic acid in green leafy vegetables.

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Effect of cooking methods on levels of folates and ascorbic acid in cowpea (Vigna unguiculata L. Walp) from Nairobi, Kenya

African Journal of Pure and Applied Sciences ◽

10.33886/ajpas.v2i1.187 ◽

2021 ◽

Vol 2 (1) ◽

pp. 53-60

Author(s):

J Mumbi ◽

R Wanjau ◽

J Murungi

Keyword(s):

Ascorbic Acid ◽

Sodium Bicarbonate ◽

Vigna Unguiculata ◽

Fruits And Vegetables ◽

Significant Loss ◽

Leafy Vegetables ◽

Cooking Methods ◽

Green Leafy Vegetables ◽

Health And Wellbeing ◽

African Indigenous Vegetables

Folate (vitamin B9,5-methyltetrahydrofolate) and ascorbic acid (AA) (vitamin C) play a key role in human health and wellbeing. It is greatly established that AA is beneficial in preventing scurvy while folate helps in prevention of neural tube defects and congenital malformations. The main sources of these vitamins are fruits and vegetables especially green leafy vegetables including the African Indigenous Vegetables (AIVs). However, these vegetables are consumed after cooking which leads to loss of the vitamins through oxidation, thermal degradation, and leaching. The study aimed at determining the effect of different cooking methods on the retention of AA and folate in cowpea (Vigna unguiculata L. Walp) as affected by different cooking methods. Folate and AA were determined using high pressure liquid chromatography with ultra UV-visible detection, HPLC-UV after extraction of the vitamins from raw and cooked samples. Analysis of Variance (ANOVA) was used to determine difference in nutrients retention by various cooking methods. Significance was imputed at p<0.05. Raw V. unguiculata ontained 45.516±0.649 mg/100g AA and 91.736±0.586 μg/100g folate. The cooked samples of the vegetable contained folate ranging from 40.713±0.081 to 65.128±0.007 μg/100g and AA ranging from 0.719±0.063 to 24.181±0.051 mg/100g of the edible portion of the vegetable. Cooking the vegetable significantly reduced both folate and AA concentration compared to the raw vegetable samples, p<0.05. Frying raw vegetables with onions and tomatoes was found to retain significant folate and AA than boiling the vegetables, p<0.05. Addition of milk resulted in significant retention of folate and significant loss of AA than boiling, p<0.05. Both lye and sodium bicarbonate significantly reduced folate and AA concentration than boiling, with lye causing significant reduction of both vitamins than sodium bicarbonate p<0.05. It is concluded that cooking reduces folate and AA concentration in cowpea (V. unguiculata L. Walp). Additive such as lye and bicarbonate also reduce the concentration of the vitamins. Cooking cowpea leaves with addition of milk and frying with onion and tomatoes retains more folate than boiling. However, AA is significantly lost in the process than when the vegetable is just boiled.

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Influence of Cooking Conditions on Nutritional Properties and Sensory Characteristics Interpreted by E-Senses: Case-Study on Selected Vegetables

Foods ◽

10.3390/foods9050607 ◽

2020 ◽

Vol 9 (5) ◽

pp. 607

Author(s):

Susanna Buratti ◽

Carola Cappa ◽

Simona Benedetti ◽

Gabriella Giovanelli

Keyword(s):

Antioxidant Activity ◽

Ascorbic Acid ◽

Nutritional Quality ◽

Total Phenolics ◽

Principal Component ◽

Sensory Characteristics ◽

Total Phenolic ◽

Cooking Methods ◽

Nutritional Properties ◽

Cooking Method

This study investigates the effects of three cooking methods (boiling, steaming and microwaving) on the nutritional and physical properties of cauliflowers, carrots and sweet potatoes; e-senses were applied to interpret the sensory characteristics according to physico-chemical aspects. The nutritional quality was evaluated by determining the concentrations of key components and the antioxidant activity; e-sense data, combined with texture parameters, were processed by a principal component analysis. The cooking method and time significantly influenced the quality of the three products. Boiling, which detrimentally affected ascorbic acid, total phenolic concentration and antioxidant activity, enhanced carotene accessibility. Steaming produced losses in ascorbic acid, increasing total phenolics and carotenoids. Microwaving resulted in minor changes in ascorbic acid concentrations, preserved carotenoids and increased total phenolics. The nutritional quality was better preserved or enhanced using shorter cooking times. The elaboration of the data collected by the e-senses showed a clear evolution according to the cooking method and time. The results helped to determine the cooking method that best preserves the nutritional properties of the vegetables, highlighting the applicability of rapid instrumental methods to interpret the evolution of sensory characteristics.

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The effect of pre-process handling conditions on the ascorbic acid content of green leafy vegetables

Food Chemistry ◽

10.1016/0308-8146(90)90187-9 ◽

1990 ◽

Vol 38 (4) ◽

pp. 297-303 ◽

Cited By ~ 8

Author(s):

O.O.P. Faboya

Keyword(s):

Ascorbic Acid ◽

Acid Content ◽

Ascorbic Acid Content ◽

Leafy Vegetables ◽

Green Leafy Vegetables

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Proximate, vitamin assays and anti-oxidant properties of an underutilised indigenous vegetable Heliotropium indicum L. (Lamiales: Boraginaceae) in West Africa in enhancing diet diversification

Revista Brasileira de Gestão Ambiental e Sustentabilidade ◽

10.21438/rbgas.030608 ◽

2016 ◽

Vol 3 (6) ◽

pp. 337-353

Author(s):

Muibat Bello ◽

Tomilayo Amusan ◽

Oluwole Oladeji

Keyword(s):

Ascorbic Acid ◽

High Performance ◽

Ascorbic Acid Content ◽

Nutritional Composition ◽

Leafy Vegetables ◽

Food Plants ◽

Sustainable Livelihood ◽

Green Leafy Vegetables ◽

Anti Oxidant ◽

Heliotropium Indicum

Green leafy vegetables are important component of human diets, providing fibre, minerals and vitamins. Recently, non-conventional food plants are incorporated in diet to provide not only nutrient but also traditional treatment for various ailments. In a way to combat the devastating effect of malnutrition, there should be a long term intervention such as dietary diversification which can be achieved by increasing the production of locally produced foods and non-conventional vegetables. This study analysed the nutritional composition and anti-oxidant potential of Heliotropium indicum L. (Lamiales: Boraginaceae). The proximate analyses were carried out using the methods described by the Association of Official Analytical Chemist (AOAC). Vitamins were quantified by high performance liquid chromatography (HPLC). Mineral content were determined by Atomic Absorption Spectrophotometric (AAS) technique. The anti-oxidant activity was tested spectrophotometrically using ascorbic and gallic acid as standards. The nutrient constituents revealed that the fat content ranged between 0.67% +/- 0.05% and ash content ranged between 15.7% +/- 0.04%. Varying levels of vitamins like ascorbic acid, retinol, tocopherols, riboflavin, thiamine and niacin was quantified in the samples. Ascorbic acid content ranged between 622.6 mg/100 g. The aqueous extracts of the samples significantly (P < 0.05) inhibited DPPH radical with an IC50 value of 38 ug/mL. It is evident from this study that these indigenous leafy vegetable which are not widely known and consumed are of high nutritional quality and anti-oxidant potential. This vegetable can contribute significantly to the nutrient requirement of man and could complement the conventional ones in enhancing food security and sustainable livelihood. Hence, their cultivation and consumption should be encouraged.

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The effect of cooking on in vitro digestibility of selected legumes

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun200957050013 ◽

2009 ◽

Vol 57 (5) ◽

pp. 13-18

Author(s):

Ranjani Amarakoon ◽

Stanislav Kráčmar ◽

Ignác Hoza ◽

Pavel Budinský

Keyword(s):

Glycine Max ◽

Pisum Sativum ◽

Dry Matter ◽

Protein Digestibility ◽

Cooking Time ◽

Cooking Methods ◽

In Vitro Digestibility ◽

Pressure Cooking ◽

Dry Matter Digestibility

The aim of this study was to investigate the effect of various cooking methods on nutritional quality by evaluating in vitro digestibility of some selected legumes (two cultivars Pisum sativum and Glycine max). Samples were soaked in 0.2% NaHCO3 for 6 hours and then cooked by normal (20, 25, 30 and 35 min) pressure (8, 10, 12 and 14 min) and microwave (8, 10, 12 and 14 min) cooking. In vitro protein and dry matter digestibility were investigated. Pressure cooking and microwave cooking are recommended after soaking with the cooking time between 8–14 mins for P. sativum (Xantos and Svit) and G. max. Based on in vitro protein digestibility of all the cooking treatments, pressure cooking is the most effective.

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Nutritional Composition of Neglected Underutilized Green Leafy Vegetables and Fruits in South East Geo-political Zone of Nigeria

Asian Food Science Journal ◽

10.9734/afsj/2019/v11i230058 ◽

2019 ◽

pp. 1-17

Author(s):

N. N. Umerah ◽

N. M. Nnam

Keyword(s):

Ascorbic Acid ◽

Vitamin E ◽

Nutrition Education ◽

Proximate Composition ◽

Fruits And Vegetables ◽

Beta Carotene ◽

Nutritional Composition ◽

Leafy Vegetables ◽

Green Leafy Vegetables ◽

Vegetables And Fruits

Background/Objective: Vegetables and fruits play a highly significant role in food security of the underprivileged in both urban and rural settings. The study was designed to determine the nutritional composition of some neglected underutilized fruits and vegetables in Southeast geopolitical zone of Nigeria. Methodology: The commonly occuring underutilized fruits and vegetables were selected for the study. The food crops were harvested and identified at the Herbarium in the Department of Plant Science and Biotechnology, University of Nigeria Nsukka. Twenty underutilized fruits and vegetables each were cleaned and analysed for nutrients composition using standard methods. Data were presented using descriptive statistics, percentage, mean, standard deviation and frequency. Results: The proximate composition of the fruits ranged from 54.34-80.30% moisture, 0.27-6.21% protein, 0-3.08% fat, 0.28-8.58 % fibre, 0.33-11.05% ash and 9.08-36.61% carbohydrate. The ranges for mineral values of the fruits were iron 0.10-9.60 mg, zinc 0.02-10.30 mg, manganese 0.10-6.60 mg and calcium 5.42-46.50 mg. The vitamin contents of the fruits ranged from beta-carotene traces -5666.67 RE, ascorbic acid 0-48.82 mg and vitamin E 0 -11.99 mg. The proximate composition of the vegetables ranged from moisture 60.45-91.00%, protein 0.02-6.60%, fat 0.02-2.19%, fibre 0.04-5.01%, ash 0.04-4.20% and carbohydrate 10.30-36.61%. The ranges for mineral values of the vegetables were iron 1.40-14.80 mg, zinc trace-9.40 mg, manganese 0.07-4.80 mg and calcium 18.19-400.00 mg. The vitamin levels of the vegetables were beta-carotene 15.20-1933.33 RE, ascorbic acid 2.40-38.40 mg and vitamin E traces - 6.67 mg. Conclusion: The use of these fruits and vegetables should be encouraged particularly in areas where they are not produced through nutrition education in order to promote the food use of these crops.

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Changes in Soluble Protein Fractions of Rice Varieties after Cooking by Different Methods

The Indian Journal of Nutrition and Dietetics ◽

10.21048/ijnd.2016.53.3.5298 ◽

2016 ◽

Vol 53 (3) ◽

pp. 277

Author(s):

Suman ◽

Pinky Boora

Keyword(s):

Soluble Protein ◽

Protein Fractions ◽

Cooking Methods ◽

Cooking Method ◽

Rice Varieties ◽

Pressure Cooking ◽

Cooked Rice ◽

Rice Samples

The aim of this research was to study the changes in soluble protein fractions of six rice varieties cooked by four cooking methods viz. ordinary, pressure, microwave and solar cooking methods. In cooked rice albumin, globulin, prolamin and glutelin fractions ranged from 4.1 to 4.3, 11.6 to 12.2, 3.0 to 3.6 and 80.5 to 81.0 % under various cooking methods against 6.4, 14.6, 4.6 and 74.4 % in the uncooked samples. Results indicated that albumin, globulin and prolamin fractions decreased significantly after cooking. This decrease was accompanied by a significant increase in the glutelin fraction as compared to uncooked rice samples. Among cooking methods, albumin in pressure and solar, globulin in solar and prolamin in ordinary were significantly (P<0.05) higher than other methods. However, in respect of glutelin content microwave and solar cooking methods were superior to ordinary but at par to pressure cooking method.

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QUANTITATIVE CHANGES OF ASCORBIC ACID AND BETA CAROTENE IN AFRICAN NIGHTSHADE (SOLANUM NIGRUM) AND SPIDER PLANT (CLEOME GYNANDRA) DUE TO TRADITIONAL COOKING METHODS USED IN WESTERN KENYA

10.37512/600 ◽

2019 ◽

Keyword(s):

Ascorbic Acid ◽

Beta Carotene ◽

Solanum Nigrum ◽

Leafy Vegetables ◽

Cooking Methods ◽

Western Kenya ◽

Cleome Gynandra ◽

Quantitative Changes ◽

Spider Plant ◽

Similar Processing

African nightshade (Solanum nigrum) and Spider plant (Cleome gynandra) are among African leafy vegetables (ALVs) that are consumed in Kenya. Studies were conducted to establish the traditional cooking methods for ALVs and to determine quantitative changes in ascorbic acid and beta carotene on cooking the two ALVs. Results revealed that the cooking methods had distinct steps. The amount of time and water for cooking were unspecified. Ascorbic acid decreased from 28.2mg/100g to 1.8mg/100g in Spider plant (93.6% loss) and from 19.5mg/100g to 5.8mg/100g in African nightshade (70% loss). Beta carotene decreased from 2.1mg/100g to 0.1mg/100g in Spider plant (94.4% loss) and from 1.8mg/100g to 0.9mg/100g (50.6% loss) in African nightshade. All results were significant (P˂ 0.001). The study concludes that there are existing methods of cooking ALVs. For the two ALVs, cooking led to drastic losses of ascorbic acid and beta carotene. Losses from the African nightshade were generally lower than from the Spider plant for the same nutrient, under similar processing conditions. The study recommends procedural changes in processing methods so as to conserve the two nutrients.

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