Nutritional Value Of Vegetables Research Articles

The proximate composition of vegetables enriched by incorporation of municipal solid waste into fertilizers and its impacts on environment and human health

The recent over production of municipal solid waste (MSW) poses a significant threat to both the ecosystem and human health. Utilizing MSW for agricultural purposes has emerged as a promising strategy to reduce solid waste disposal while simultaneously increasing soil fertility. To explore this potential solution further, an experiment was designed to assess the impact of varying concentrations of MSW (25%, 50%, and 75%) on the proximate composition of 15 different vegetable species. The experiment, conducted between 2018 and 2019, involved treating soil with different levels of solid waste and analyzing the proximate components, such as crude protein, dry matter, crude fiber, crude fat, and moisture content, in the 15 selected crops. The results indicate that the application of 25% MSW significantly increased the levels of crude protein, crude fiber, dry matter, and fat in Spinacia oleracea, Solanum tuberosum, Solanum melongena, and Abelmoschus esculentus. Conversely, the addition of 75% MSW notably elevated the moisture and ash content in Cucumis sativus. Correlation and scatter matrix analyses were conducted to elucidate the relationships between the protein, fiber, dry matter, ash, and fat contents. Principal component analysis and clustering confirmed the substantial impact of Treatment_1 (25% MSW) and Treatment_3 (75% MSW) on the proximate composition of the aforementioned vegetables, leading to their categorization into distinct groups. Our study highlights the efficacy of using 25% MSW to enhance the proximate composition and nutritional value of vegetables. Nonetheless, further research is warranted to investigate the mineral, antioxidant, vitamin, and heavy metal contents in the soil over an extended period of MSW application.

Elemental composition and potential health risk of vegetable cultivated in residential area situated close to abandoned gold mine dump: Characteristics of soil quality on the vegetables

The presence of toxic metals in residential areas near abandoned gold mine tailings is a major environmental issue. This study mainly aimed to investigate the elemental distribution of both toxic and essential elements in soils and leafy vegetables (Brassica oleracea) collected from eight different sites around the Davidsonville residential area, located closer to the abandoned Princess gold mine dump, Johannesburg, South Africa. The nutritional value of vegetables in the human diet was determined to assess their value to their health. The vegetables contained metals in the following descending order: Ca > Mg > Ca > Sb > Pb > Fe > Mo > Cr > Se > As > V > Ni > Co > Cd. The bioaccumulation factor (BAF) revealed that vegetables tend to accumulate most metals even (toxic) during the transfer and translocation process. Based on the recommended daily allowance (%RDA) the vegetables showed to contribute 152%, 84% and 75% toward RDA for Se, V and Ca, respectively for most adults and these play a role in human metabolic activities. The vegetables were found to be a good source of essential elements (Ca, Mg, Ni, Na, Fe) but with some traces of toxic metals such as Pb, As and Sb. Based on the health risk assessment, the vegetable posed an adverse health hazard for human consumption due to metals with high HRI >1.

Methodological pipeline for monitoring post-harvest quality of leafy vegetables

Plants are primary source of nutrients for humans. However, the nutritional value of vegetables tends to decrease once organ and tissue sinks are detached from the plant. Minimal processing of leafy vegetables involves cutting and washing before packaging and storage. These processing procedures result in stressful conditions and post-harvest disorders senescence-related can also occur. The aim of this work is to define a methodological pipeline to evaluate the “quality” changes of fresh cut leafy vegetables over their shelf-life. At this purpose, intra-species variability has been investigated considering two varieties of Lactuca sativa (var. longifolia and capitata), showing different susceptibility to browning. Since browning mainly depends on phenol oxidation, redox parameters as well as the activity of the enzymes involved in phenol biosynthesis and oxidation have been monitored over storage time. At the same time, the metabolic changes of the lettuce leaves have been estimated as response patterns to chemical sensors. The obtained sensor outputs were predictive of browning-related biological features in a cultivar-dependent manner. The integration of the results obtained by this multivariate methodological approach allowed the identification of the most appropriate quality markers in lettuce leaves from different varieties. This methodological pipeline is proposed for the identification and subsequent monitoring of post-harvest quality of leafy vegetables.

Characterization of Polyphenol Oxidase from Eruca sativa

Enzymatic browning reactions by polyphenol oxidases cause alteration of appearance, flavor and nutritive value of vegetables and fruits. It is one of the important problems for vegetables used as salads and causes lots of economic losses. In this study, polyphenol oxidase (PPO) from Eruca sativa was extracted and characterization studies were carried out. Substrate specificity for variable substrates, optimum pH, optimum temperature, effect of different metal ions were assayed. Km and Vmax values were determined as for pyrocatechol Km = 10.24 mM, Vmax = 0.0018 U min-1, catechin; Km = 12.57 mM, Vmax = 0.0012 U min-1, gallic acid; Km = 23.07 mM, Vmax = 0.0001 U min-1. Optimum pH and temperature were determined as pH:7.0 and 20 oC respectively. Effect of various metal ions such as, K+, Fe2+, Mg2+, Zn2+, Cu2+ and Hg2+ on enzyme activity were measured. K+, Mg2+, Zn2+, Cu2+ ions inhibited PPO activity significantly. However Fe2+ ion did not inhibit PPO activity.

A novel HPLC-MS/MS approach for the identification of biological thiols in vegetables

Thiols are important natural molecules with diverse functions, ranging from acting as antioxidants that prevent chronic diseases to contributing aromas to foods and beverages. Biological thiols such as glutathione are of particular interest due to their functional roles, which include helping maintain cellular redox homeostasis and detoxifying reactive oxygen species. However, knowledge of thiol metabolism in plants is limited to studying known compounds, whereas other important thiol-containing metabolites could also exist. This work aimed to develop a new analytical approach for screening of thiols in plants, using four vegetal examples and beginning with HPLC-MS/MS in precursor ion scan mode, after extraction and thiol-specific derivatisation with 4,4′-dithiodipyridine (DTDP). Compound identity for prospective thiols was then proposed using HPLC with high resolution MS, and verified with authentic standards. This approach could lead to prospecting studies that identify thiols with potential roles in metabolic pathways, nutritional value of vegetables, or flavouring of foods.

Meloidogyne javanica parasitism on the vegetative growth and nutritional quality of carrots

ABSTRACT: Meloidogyne javanica is a plant-parasitic nematode that infects a wide range of vegetables. Its negative effects on crop yield and value are well documented. However, few studies have investigated the impact of the parasite on the nutritional value of vegetables. This study aimed to assess the effect of M. javanica parasitism on the vegetative characteristics, nematological parameters, chemistry composition and antioxidant activity of carrots. Seedlings were inoculated with 0 (control), 1000, 2500, or 5000 eggs and eventual second-stage juveniles (J2) of M. javanica. At 60 days after inoculation, plants were harvested and evaluated. Plants inoculated with 2500 eggs and J2 of M. javanica had higher root and tuber fresh weight than the control. Gall number increased with increasing inoculum density. The number of nematodes in the roots increased until 3000 specimens, decreasing thereafter. Proximate analysis revealed that plants inoculated with 1000 eggs and J2 of M. javanica or more had higher protein content in roots. In contrast, inoculation with 1775 nematodes or more resulted in a decrease in carotenoid content. There was no effect of inoculation on total phenolic content or antioxidant activity. Although, M. javanica infection did not have a marked impact on the nutritional quality of carrots, gall formation resulted in deformed roots of low commercial value.

ABA signalling manipulation suppresses senescence of a leafy vegetable stored at room temperature.

SummaryPostharvest senescence and associated stresses limit the shelf life and nutritional value of vegetables. Improved understanding of these processes creates options for better management. After harvest, controlled exposure to abiotic stresses and/or exogenous phytohormones can enhance nutraceutical, organoleptic and commercial longevity traits. With leaf senescence, abscisic acid (ABA) contents progressively rise, but the actual biological functions of this hormone through senescence still need to be clarified. Postharvest senescence of detached green cabbage leaves (Brassica oleracea var. capitata) was characterized under cold (4 °C) and room temperature (25 °C) storage conditions. Hormonal profiling of regions of the leaf blade (apical, medial, basal) revealed a decrease in cytokinins contents during the first days under both conditions, while ABA only increased at 25 °C. Treatments with ABA and a partial agonist of ABA (pyrabactin) for 8 days did not lead to significant effects on water and pigment contents, but increased cell integrity and altered 1‐aminocyclopropane‐1‐carboxylic acid (ACC) and cytokinins contents. Transcriptome analysis showed transcriptional regulation of ABA, cytokinin and ethylene metabolism and signalling; proteasome components; senescence regulation; protection of chloroplast functionality and cell homeostasis; and suppression of defence responses (including glucosinolates and phenylpropanoids metabolism). It is concluded that increasing the concentration of ABA (or its partial agonist pyrabactin) from the start of postharvest suppresses senescence of stored leaves, changes the transcriptional regulation of glucosinolates metabolism and down‐regulates biotic stress defence mechanisms. These results suggest a potential for manipulating ABA signalling for improving postharvest quality of leafy vegetables stored at ambient temperature.

Investigation of the Potential Health Benefits as Lipase Inhibitor and Antioxidant of Leopoldia comosa (L.) Parl.: Variability of Chemical Composition of Wild and Cultivated Bulbs.

There is a great interest in the nutritional value of vegetables and fruits and how the habitat affects nutritive and biological properties. In vitro studies here reported were performed to evaluate the inhibitory activity of formulations from edible plant on pancreatic lipase. The aim of this study was also to evaluate the biovariability of L. comosa (L.) Parl. bulbs from Italy. The wild bulbs were compared with the same cultivated species that are commonly commercialized to identify samples with the best quality for a potential therapeutic application. Hydroalcoholic extract and polar fraction of wild bulbs showed a very important pancreatic lipase inhibitory activity, with IC50 values of 0.166±0.005 and 0.153±0.005mg/mL, respectively. In order to characterize the extracts, gas chromatography associated with mass spectrometry (GC/MS) analysis was performed, revealing the predominance of palmitic acid. Phenolic and flavonoid composition was also evaluated. L. comosa extract obtained from wild bulbs demonstrated both antioxidant and anti-obesity activities that might be attributed to a wide range of present phenolic compounds.

Effect of Salt Stress on Nutritional Value of Vegetables

Vegetables serve as a source of pharmacologically active molecules. However, due to increased environmental stresses the concentration of bioactive compounds and the valuable constituents of vegetables are getting deteriorated day by day. Salt stress is one of the major environmental stresses affecting the plants nutritional value. Salt stress influences the plant growth by inducing adverse effects on different physiological and biochemical processes and thus leads to nutrient disorder. Therefore, there is a need to develop some tools/techniques which would be helpful for the farmers whose soil or irrigation water are saline as well as those people who frequently consume vegetables for nutritional purposes.

Quality and nutritional value of vegetables from organic and conventional farming

Consumers demand for healthier food and governments’ policies for environmental sustainability of agricultural processes are increasingly promoting a rapid expansion of organic farming. Nevertheless, the link between organic products and their enhanced nutritional/environmental values is far from being fully understood. In this context, we have begun to assess the effect of cultivation variables that may interact with farming systems and ultimately affect the final product quality. By comparing the response to conventional vs. organic farming of cauliflower, endive and zucchini here we demonstrate that the overall quality of organic products depends on many interacting variables. In cauliflower, the cultivar effect overwhelms other quality determinants with respect to antioxidant activity and nitrate accumulation. In endive, the liposoluble antioxidant activity increases under organic cultivation only in the absence of mulching. Finally, organic farming promotes the accumulation of K in zucchini grown on clay but not on sandy soil. Therefore, understanding the functional links between cultivation variables and physiological responses is essential to improve and standardize the quality of organic products.

광주·전남 일부지역 초등학생의 채소류 섭취에 대한 인식

The purpose of this study was to analyze the dietary habits and perception of vegetable intake of elementary students in Gwangju and Jeonnam Gokseong county. Data collection was conducted from 5th and 6th grade students of elementary schools in Gwangju and Jeonnam Gokseong county using a structured questionnaire survey. The SPSS program was used for statistics processing and data analysis. The chi-square test was also conducted. In terms of dietary intake habits, female students consumed their meals slower than male students. Information on dietary habits and nutrition was commonly obtained from family, including the mother or father who commonly prepared meals at home. Snacks were commonly consumed less than twice daily, with the Gwangju area having a higher frequency of snacks than the Jeonnam area. Elementary students indicated that vegetables were their least favorite food, with female students having a higher interest in vegetables than male students. The pattern and perception of vegetable intake came when the students (that did not eat vegetables) were lectured by their parents on the nutritive value of vegetables. Most students understood the important nutritional ingredients of vegetables. In the case of an interest in vegetables, the Gwangju area showed significantly more comprehension than the Jeonnam area on the definition and role of dietary fiber, the dental benefits of dietary fiber, and the identification of the environment-friendly certification mark.

Prevelance of total coliforms, faecal coliforms and <i>E. coli</i> in Rawalpindi vegetable markets

Nutritional value of vegetables and high prices of meat and meat originated food compel common people to consume plant originated food particularly salad vegetables. Microbial population of vegetable surfaces contains a large number of pathogenic bacteria including members of Enterobactereace like Escherichia coli (E. coli). A survey was conducted in three major markets of Rawalpindi, Pakistan. Tomato, lettuce, cabbage and cucumber samples were collected from three shops of each market. Each vegetable was analysed as unwashed and washed for total coliforms, faecal coliforms and E. coli by FAO (Food Quality Manual). About two hundred and fifty E. coli isolates were preserved, serotyped for presence of O157 serotype. Total coliforms, faecal coliforms and E. coli count exceeded the permissible limits in most samples. The highest Total coliforms were associated with cabbage (3.78 log10 cfu/g). Cucumber was the least contaminated by Total coliforms (2.15 log10 cfu/g). E. coli was detected in tomato, lettuce, cucumber and cabbage. Washed samples showed reduced bacterial population. Seventy six isolates of E. coli were biochemically characterized and serotyped for O157 antigen. A majority of strains could not be identified by serotyping. These findings conclude with high potentially pathogenic microbial load on salad vegetables and urge for preventive action on priority basis.

Mineral and Ascorbic Acid Concentrations of Greenhouse- and Field-Grown Vegetables: Implications for Human Health

Vegetable nutritional quality is related to concentrations of antioxidants and other phytonutrients. In Iran, vegetables can be produced in soil in climate-controlled greenhouses. Limited information is available on the quality of greenhouse-grown vegetables compared to field-grown vegetables. Concentrations of Ca, Mg, P, K, Fe, Zn, Cu, Mn, and ascorbic acid in greenhouse- and field-grown bell pepper (Capsicum annuum L.), cucumber (Cucumis sativa L.), and tomato (Solanum lycopersicum L.) were determined. Mean fruit K, P, and Mg concentrations in greenhouse-grown bell pepper, cucumber, and tomato were greater than expected levels. Mean fruit K concentrations in greenhouse-grown bell pepper, cucumber, and tomato were lower than that in field-grown vegetables. Greenhouse-grown vegetables accumulated greater amounts of P in fruit compared to field-grown vegetables. More than 48%, 38%, 30%, and 54% of greenhouse vegetables were Fe, Zn, Cu, and Mn deficient, respectively. Field-grown vegetables had lower contents of Cu, Mn, Fe, Zn, and ascorbic acid compared to greenhouse-grown vegetables. Calcium, Fe, Cu, Mn, and Zn intakes through consumption of greenhouse-grown vegetables for population study groups accounted for a negligible fraction of the recommended daily allowance (RDA), whereas daily intake of ascorbic acid was greater than the RDA requirement. Intake of micronutrients and ascorbic acid from field-grown vegetables was less than that from greenhouse-grown vegetables. In general, the nutritional quality (contents of micronutrients and ascorbic acid) of greenhouse-grown vegetables was better than that of field-grown vegetables, although fruit micronutrient concentrations of field- and greenhouse-grown vegetables were lower than expected levels. The results indicated that bell pepper is an excellent source of ascorbic acid and potassium for humans. Despite a protected system of cultivation, poor fertilizer management in greenhouses could adversely affect the nutritional value of vegetables. Improved nutritional management in greenhouses could enhance micronutrient concentrations in these vegetables.

Studying the oxidation and the antiradical activity of betalain from beetroot

Betalains, the pigments responsible for the colour of beetroots, and peroxidases coexist in the same tissue but are compartmentalised. Beetroot storage and/or processing breaks down the compartments, resulting in betalain oxidation and colour loss. This can be observed using two simple techniques (centrifugation and spectrophotometry). The in vitro oxidation of betalains by the H202/peroxidase system clearly demonstrates the fate of these pigments when beetroots are degraded in vivo during postharvest storage and /or industrial processing. The health giving properties of fresh vegetables directly depends on phenolic compounds and the antioxidant capacity that they have, since these compounds act as free radical scavengers preventing activated oxygen species from oxidising biological tissues. Therefore the measurement of antioxidant capacity reveals much about the nutritional value of vegetables: the greater their antiradical activity, the greater their capacity for scavenging free radicals. This paper is intended for biochemistry and food technology students with a knowledge of spectrometry and centrifugation techniques, who wish to deepen their knowledge of the important alterations that occur in the organoleptic characteristics of fresh fruit and vegetables.

Comparative study of frying to other cooking techniques influence on the nutritive value

Frying is one of the oldest methods of food preparation. It improves the sensory quality of food by formation of aroma compounds, attractive colour, crust and texture. Undesirable changes involved are loss of nutritive quality e.g. due to degradation of heat - susceptible vitamins. The influence of common frying methods (frying in an oven, in a pan deep frying) on cooking time and nutritive value of vegetables, potatoes, meat, poultry and fish is described and compared to other cooking methods (boiling, steaming, stewing). Frying of vegetables, potatoes and breaded meat, poultry and fish, no matter whether in a pan or by deep - frying, is associated with fat uptake (2 - 14 g per 100 g of raw food) while non - breaded high fat food of animal origin loses fat during frying (2 - 30%). Data suggest that the fat quantity absorbed during frying increases up to a saturation limit which depends on the kind of food and on the amount of panade. Deep - fried meat, poultry and fish usually absorb less fat than meat, poultry and fish fried in a pan. The kind of fat had no essential influence on fat uptake. After frying of vegetable food and of breaded meat, poultry and fish, the content of protein, carbohydrates and minerals was nearly fully retained while boiling and steaming reduced the mineral content by 25-50%. In the majority of cases frying including deep frying also retained the vitamins B 1 , B 2 , B 6 and C better than boiling, steaming and stewing.

Preharvest Factors Affecting Postharvest Quality of Vegetables

Vegetables provide a major source of essential vitamins such as ascorbic acid and beta carotene and other quality components in the human diet. Postharvest yield and quality of vegetables depend upon genetic, biotic, edaphic, chemic and other factors, as well as combinations of these factors. Successful production, quality and nutritional value of vegetables are related to both primary and secondary metabolic processes occurring during vegetable growth and development. Related research has focused upon cultivar selection, cultural practices used during production, interaction of light and temperature, and use of chemicals for growth regulation, and pest control. We will discuss the effects of genetic, pest, and soil management; crop maturity at harvest; environmental modification; and climatic conditions. Postharvest vegetable quality will be characterized in terms of vitamin content, appearance, yield, and flavor.

Vegetable growing handbook: organic and traditional methods

Planning the garden. Plant growth. Soils and plant nutrition. Pest control. Harvest and storage of vegetables. Nutritional value of vegetables. Growing common vegetables. Growing special-use vegetables. Growing and preserving herbs.