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Seasonal Variability in the Vitamin C Content of Fresh Fruits and Vegetables in a Local Retail Market: Seasonal variation of vitamin C in fresh fruits and vegetables in retail market
Abstract
Background:
Seasonal variation of vitamin C in fresh fruits and vegetables is not reflected in food composition database average values, yet many factors influence content and retention.
Results:
Fresh fruits and vegetables were sampled on three occasions in each season, from the same local retail outlets, for one or two years. Vitamin C was significantly higher in winter-sampled spinach (436 mg kg-1 ) compared to spring (298) and summer/fall (180); in potatoes in summer/fall (156) versus winter/spring (106); and oranges in winter (616), spring (592), and summer (506). Ranges were dramatic among sampling occasions for broccoli, oranges, potatoes, spinach (700-1210, 420-780, 70-280, and 90-660 mg kg-1 , respectively). Mean values for apples, bananas, tomatoes, and potatoes differed from the USDA National Nutrient Database for Standard Reference (SR) average by ≥10% of the Daily Recommended Intake (90 mg). For broccoli, oranges, and spinach vitamin C was substantially above or below the SR range in 50-100% of the samples. For spinach, the average content did not differ from SR, but vitamin C in winter was 55% higher than SR.
Conclusion:
Database average values for vitamin C in fresh produce can significantly over-or underestimate the content in a specific food supply.
... In plants, vitamin C plays many roles, and the content of Vitamin C in plants varies greatly depending on cultivar, growing conditions, maturity at harvest, and postharvest handling, processing, and storage (Phillips et al., 2018). In the human body, vitamin C plays many roles, including the ability to act as a water-soluble antioxidant, aid in collagen synthesis, increase absorption of iron from the diet and plays other critical roles in the metabolism of folate and some amino acids (Phillips et al., 2018). ...
... In plants, vitamin C plays many roles, and the content of Vitamin C in plants varies greatly depending on cultivar, growing conditions, maturity at harvest, and postharvest handling, processing, and storage (Phillips et al., 2018). In the human body, vitamin C plays many roles, including the ability to act as a water-soluble antioxidant, aid in collagen synthesis, increase absorption of iron from the diet and plays other critical roles in the metabolism of folate and some amino acids (Phillips et al., 2018). Dietary fiber is a critical shortfall nutrient in the United States. ...
... plant stage at harvest, storage temperature and wide range of postharvest conditions (Phillips et al., 2018). Traditionally, accumulation of vitamin C is increased whenever plants are exposed to high oxidative stress, including full sunlight, low nitrogen availability in the soil and drought conditions (Kaack et al., 2001). ...
Arugula ( Eruca sativa ), mizuna ( Brassica rapa var. nipponsinca ), red giant mustard ( Brassica juncea ), and spinach ( Spinaciaoleracea “Tyee”) are fresh produce crops high in nutritive value that provide shortfall and high interest nutrients addressed in the U.S. Dietary Guidelines. The primary objective of this project was to evaluate fertility treatments unique to these crops that optimize their nutritional capacity. Measurements discussed include: vitamin C, dietary fiber, calcium, iron, potassium, sodium, and nitrate. Plants were grown at the University of Minnesota St. Paul Campus (St. Paul, MN) in a greenhouse from November to April under an 18 h photoperiod and a 24/13°C day/night temperature. Plants were grown using five different fertility treatments, including four organic treatments and one conventional control. The plant treatment combinations were replicated three times and the entire experiment was duplicated. Fertility treatments had a high impact on vitamin C (with over a 3-fold difference in treatments in the first experiment), nitrate (over 10-fold difference among fertility treatments in some species) and potassium concentrations (over 5-fold difference among fertility treatments in some species) in analyzed plant tissue. No consistent differences were found for fiber, calcium, iron and sodium concentrations in tissue analyzed. This is the first study to analyze the impact that different organic treatments can have on multiple nutrients and compounds addressed by the U.S. Dietary Guidelines for high-impact, highly-consumed produce crops.
... Therefore, the consumption of seasonal, fresh food is generally more favorable. Considering that athletes often eat in dining halls of institutions or training centers, planning menus for athletes should favor fresh seasonal fruits and vegetables, as packaged, processed, frozen, or canned foods not only elevate the environmental impacts [37,[60][61][62][63] but also may compromise flavor and nutrition [64][65][66]. In a recent study performed at an elite training center, higher environmental impacts were identified from frozen and canned vegetables compared to fresh options (Reguant-Closa et al., under review). ...
... In a recent study performed at an elite training center, higher environmental impacts were identified from frozen and canned vegetables compared to fresh options (Reguant-Closa et al., under review). While food service and support staff or athletes may not always know when produce is in season or the nutritional, flavor, and environmental ramifications of outof-season products [64,66,67], food literacy approaches can remedy such gaps. ...
Purpose of review:
Sustainable production and healthy consumption have been the topic of recent publications. Due to the high environmental impact of the current food system, significant changes in how food is produced, distributed, and consumed are needed in all sectors and groups. While most research in sustainable diets has focused on the general population, limited work has involved athletes. The purpose of this review is to summarize the current knowledge on food and sustainability in athletes.
Recent findings:
Meeting but not exceeding protein requirements through flexitarian and plant-based approaches, reducing packaged foods and food waste, and prioritizing seasonal produce were identified as possible mitigation options in athletes. There is urgency for more research on plant-centric, whole food-based strategies for post-exercise skeletal muscle and training adaptation, the effect of sustainable diets on health and performance, and behaviors to reduce packaging and food waste in athletes.
... Quinoa leaves contain vitamin A (2085 mg) and a small amount of vitamin E (2.9 mg 100 g −1 ) [57]. Common leafy green spinach contains vitamin C ranging from 30 to 130 mg 100 g −1 [58,59]. However, quinoa grains contain 16 mg 100 g −1 , whereas wheat, corn, and rice contain non-traceable amounts of vitamin C [60,61]. ...
Quinoa (Chenopodium quinoa Willd.) is a nutrient-rich grain native to South America and eaten worldwide as a healthy food, sometimes even referred to as a ”superfood”. Like quinoa grains, quinoa greens (green leaves, sprouts, and microgreens) are also rich in nutrients and have health promoting properties such as being antimicrobial, anticancer, antidiabetic, antioxidant, antiobesity, and cardio-beneficial. Quinoa greens are gluten-free and provide an excellent source of protein, amino acids, essential minerals, and omega-3 fatty acids. Quinoa greens represent a promising value-added vegetable that could resolve malnutrition problems and contribute to food and nutritional security. The greens can be grown year-round (in the field, high tunnel, and greenhouse) and have short growth durations. In addition, quinoa is salt-, drought-, and cold-tolerant and requires little fertilizer and water to grow. Nevertheless, consumption of quinoa greens as leafy vegetables is uncommon. To date, only a few researchers have investigated the nutritional properties, phytochemical composition, and human health benefits of quinoa greens. We undertook a comprehensive review of the literature on quinoa greens to explore their nutritional and functional significance to human health and to bring awareness to their use in human diets.
... The fruit was then cut with a stainless steel paring knife into~1-cm thick slices, immediately frozen in liquid nitrogen, and homogenized in liquid nitrogen using a 6-L Robot Coupe Blixer food processor (Robot Coupe USA. Jackson, MS) as described elsewhere [17], with subsamples (10-15 g each) for analysis of sugars, starch, dietary fiber, and moisture dispensed among 60-mL glass jars with Teflon™ lined lids (Qorpak. Clinton, PA) and immediately frozen at -60˚C. ...
The goal of this work was to evaluate changes in dietary fiber measured by the traditional enzymatic-gravimetric method (AOAC 991.43) and the more recently accepted modified enzymatic-gravimetric method (AOAC 2011.25), mono- and disaccharides, and starch as a function of assessed ripeness in a controlled study of a single lot of bananas and in bananas at the same assessed stages of ripeness from bananas purchased in retail stores, from different suppliers. Sugars, starch, and dietary fiber were analyzed in bananas from a single lot, at different stages of ripeness, and in retail samples at the same assessed stages of ripeness. Mean fiber measured by the traditional enzymatic-gravimetric method (EG) was ~2 g/100g and not affected by ripeness. Mean fiber assessed with the recently modified method (mEG) was ~18 g/100g in unripe fruit and decreased to 4–5 g/100g in ripe and ~2 g/100g in overripe bananas. Slightly ripe and ripe bananas differed by ~1.1 g/100g in the controlled single-lot study but not among retail samples. There was a large increase in fructose, glucose and total sugar going from unripe to ripe with no differences between ripe and overripe. Aside from stage of ripeness, the carbohydrate composition in retail bananas is likely affected by differences in cultivar and post-harvest handling. Results from this study demonstrate the importance of measuring dietary fiber using the mEG approach, developing more comprehensive and sensitive carbohydrate analytical protocols and food composition data, and recognizing the impact of different stages of maturity and ripeness on carbohydrate intake estimated from food composition data.
... sagittifolium). Although the vitamin C content from X. sagittifolium, H. sabdariffa, and H. acetosella was lower than other fruits and vegetables, like oranges, broccoli, and spinach, this vitamin C content is still comparable to those reported for apples, lettuce, and peaches (Phillips et al., 2018). In general, the leaves seem to be a good source of vitamin C and could be used to support the daily needs of this important micronutrient. ...
This study investigated the vitamin C content, total phenolic compounds (TPC), and the potential bioactivities (antioxidant, antiproliferative, antibacterial activities, and inhibition capacity against N-nitrosation) of seven neglected and underutilized species (NUS): culantro (Eryngium foetidum), false roselle (Hibiscus acetosella), roselle (Hibiscus sabdariffa), tree basil (Ocimum gratissimum), Barbados Gooseberry (Pereskia aculeata), purslane (Portulaca oleracea), and tannia (Xanthosoma sagittifolium). Phenolic-rich extracts were obtained by a sequential optimization strategy (Plackett-Burman and Central Composite Design). O. gratissimum presented the highest TPC and X. sagittifolium the greater total vitamin C content. Overall, the plant extracts presented promising bioactive capacities, as scavenging capacity against HOCl, H2O2 and ROO• induced oxidation. P. oleracea demonstrated the highest cytostatic effect against ovarian and kidney tumor cells. O. gratissimum effectively inhibited S. Choleraesuis growth. Maximum inhibition on n-nitrosation was showed by O. gratissimum and E. foetidum. These results highlight the studied NUS as sources of potential health-promoting compounds.
... Ascorbic acid is an essential nutrient with powerful reducing proprieties. It is contained in fresh fruits and not in cooked vegetables, with different percentage depending on the season [93]. It can react with superoxide, hydrogen peroxide, hypochlorite, hydroxyl and peroxyl radicals, and singlet oxygen [94]. ...
Porphyria refers to a group of fascinating diseases from a metabolic and nutritional standpoint as it provides an example of how metabolic manipulation can be used for therapeutic purposes. It is characterized by defects in heme synthesis, particularly in the erythrocytes and liver. Specific enzymes involved in heme biosynthesis directly depend on adequate levels of vitamins and minerals in the tissues. Moreover, micronutrients that are required for producing succinyl CoA and other intermediates in the Krebs (TCA) cycle are indirectly necessary for heme metabolism. This review summarizes articles that describe the nutritional status, supplements intake, and dietary practices of patients affected by porphyria, paying special attention to the therapeutic use of nutrients that may help or hinder this group of diseases.
... In leaves obtained from C2, ASA content decreased during cold storage, declining by 60% at the end of storage as compared to values at harvest (Figure 3). However, ASA levels in this species were close to those found in leafy vegetables considered a good source of vitamin C, like spinach (Spinacia oleracea) [29][30][31]. The content of ASA in leaves is related also to the season of cultivation and, in this sense, Phillips et al. [30] reported that in spinach the ASA content averaged 0.44, 0.30, 0.18, and 0.18 mg g -1 FW when grown in winter, spring, summer, and fall, respectively. ...
Sorrel (Rumex acetosa L.) is a perennial wild herb appreciated as a folk medicine and for use in folk-traditional cuisines, and its nutraceutical properties are increasingly known and studied. Nowadays, there is a lack of knowledge about the possibility of using this species as fresh-cut produce, and no reports have investigated the physiological/biochemical changes of sorrel leaves upon storage. To test the aforementioned, sorrel seedlings were cultivated in a floating system and two consecutive harvests took place: the first cut at 15 days (C1) and second cut at 30 days (C2) after sowing. Fresh-cut sorrel leaves from C1 and C2 were stored in plastic boxes at 4 °C for 15 days and chlorophylls, carotenoids, total phenols, flavonoids, ascorbic acid, and antioxidant capacity were evaluated during the storage period. During storage, sorrel leaves from the same cut did not show significant changes in total phenolic content and antioxidant capacity, which represents a positive outcome for the maintenance of the nutraceutical value of this species. For this reason, sorrel may be a very promising species as a "new" fresh-cut leafy vegetable. However, some differences were observed between the two cuts, especially in the total flavonoid and the total ascorbic acid contents. While promising, further research will be necessary to standardize the yield and the nutraceutical content of this species in different cuts, which will be necessary to introduce and promote sorrel to consumers.
... The consumption of all seasonal fruit and vegetables is encouraged because fruits and vegetables grown in season are richer in nutrients (especially vitamins and minerals) and usually undergo less processing, packaging, transportation and storage. 39,40 Raw tomatoes, eggplants, and peppers all contain substances (glycoalkaloids and polyamines) that can increase inflammation and intestinal cancerogenesis, so are best avoided. [41][42][43] Japanese fermented foods (miso, soy sauce, tempeh) are included too, to facilitate digestion and serve as a reliable reservoir for microbiota. ...
Patients with familial adenomatous polyposis (FAP) depend on a lifelong endoscopic surveillance programme and prophylactic surgery, and usually suffer nutritional problems. Intestinal inflammation has been linked to both FAP and colorectal cancer. Epidemiological studies show a relationship between diet and inflammation. Preventive dietary recommendations for FAP patients are so far lacking. We have designed a nonrandomized prospective pilot study on FAP patients to assess whether a low-inflammatory diet based on the Mediterranean diet principles and recipes, by interacting with the microbiota, reduces gastrointestinal markers of inflammation and improves quality of life. This report describes the scientific protocol of the study and reports the participants’ adherence to the proposed dietary recommendations. Thirty-four FAP patients older than 18 years, bearing the APC pathogenic variant, who underwent prophylactic total colectomy with ileo-rectal anastomosis were eligible into the study. During the 3-month dietary intervention, they reported improvements in their consumption of Mediterranean foods (vegetables, fruits, fish, and legumes), and a reduction in pro-inflammatory foods (red/processed meat and sweets); this led to a significant increase in their adherence to the Mediterranean diet. The improvement was accompanied by a decrease in the number of diarrhoeal discharges. These preliminary results are encouraging with regard to feasibility, dietary outcome measures, and safety.
Objectives:
Canary Islands bananas represent the only native cultivar of Musa spp. present in Spanish territory. Since 2013, it has the Protected Geographical Indication label, which confers an additional value to this fruit. Bananas from the Canary Islands have certain organoleptic properties that make them stand out from among other commonly consumed Musa spp. However, to date, no studies have been reported including an extended nutritional composition of this product.
Methods:
the present work shows the main nutritional components of bananas from the Canary Islands as determined by different analytical techniques (mainly liquid chromatography, spectroscopy, spectrophotometry, and polarimetry) when at their best in terms of ripeness (grade 6). Moreover, potential nutrition claims relating to their composition were proposed using the current legislation.
Results:
the fruit's remarkable content in vitamin B6 (0.52 g/100 g), dietary fiber (2.22 g/100 g), potassium (419.9 mg/100 g), and vitamin C (12.35 mg/100 g) should be highlighted. Additionally, these components could appear on nutritional labeling as claims, according to current European regulations.
Conclusions:
a daily consumption of one Canary Islands banana contributes to the recommended dietary intake of vitamin B6, vitamin C, potassium, and dietary fiber. The high nutritional value of this fruit enhances its presence in the Mediterranean eating pattern, being remarkable as a local product with excellent nutritional properties.
Peripheral artery disease (PAD) is caused by atherosclerosis and associated with an increased risk of leg amputation, cardiovascular disease, and death. A healthy diet has been shown to reduce the risk of cardiovascular events, but relationships between diet, fiber intake, and incidence of PAD are virtually unknown. The aim was to investigate the long-term impact of diet on the development of PAD among 26,010 middle-aged individuals in the prospective Malmö Diet and Cancer study (MDCS). Data on dietary intake were collected through a 7-day food diary combined with a food questionnaire and a 1-hour interview. Adherence to a recommended intake of six dietary components – saturated fat, polyunsaturated fat, fish and shellfish, fiber, fruit and vegetables, and sucrose – was scored (sum 0–6 points) to assess a diet quality index, adjusting for potential confounders. Cox regression analysis was used to estimate associations between diet variables and PAD incidence expressed in hazard ratios (HR) with 95% CI. During a median follow-up of 21.7 years, 1122 participants developed PAD. Diet score was associated with a reduced risk of PAD in multivariable analysis ( p = 0.03). When mutually adjusting for all dietary variables, only adherence to recommended levels of fiber intake was associated with a reduced risk of incident PAD (HR 0.84; 95% CI 0.72–0.99). In this prospective, population-based study including 26,010 participants with over 20 years of follow-up, a healthy diet, especially a high intake of fiber, was associated with a reduced risk of PAD. Primary prevention programs directed against PAD should therefore include a fiber recommendation.
Vitamin C is a powerful dietary antioxidant that has received considerable attention in the literature related to its possible role in heart health. Although classical vitamin C deficiency, marked by scurvy, is rare in most parts of the world, some research has shown variable heart disease risks depending on plasma vitamin C concentration, even within the normal range. Furthermore, other studies have suggested possible heart-related benefits to vitamin C taken in doses beyond the minimal amounts required to prevent classically defined deficiency. The objective of this review is to systematically review the findings of existing epidemiologic research on vitamin C and its potential role in cardiovascular disease (CVD). It is well established that vitamin C inhibits oxidation of LDL-protein, thereby reducing atherosclerosis, but the cardiovascular outcomes related to this action and other actions of vitamin C are not fully understood. Randomized controlled trials as well as observational cohort studies have investigated this topic with varying results. Vitamin C has been linked in some work to improvements in lipid profiles, arterial stiffness, and endothelial function. However, other studies have failed to confirm these results, and observational cohort studies are varied in their findings on the vitamin's effect on CVD risk and mortality. Overall, current research suggests that vitamin C deficiency is associated with a higher risk of mortality from CVD and that vitamin C may slightly improve endothelial function and lipid profiles in some groups, especially those with low plasma vitamin C levels. However, the current literature provides little support for the widespread use of vitamin C supplementation to reduce CVD risk or mortality.
The National Food and Nutrient Analysis Program (NFNAP) was implemented in 1997 as a collaborative food composition research effort between USDA and NIH. The goal of this program is to obtain nationally representative estimates of the nutritional components of important foods consumed in the US for inclusion in the USDA National Nutrient Databank System; to date, analytical food composition data generated for over 1800 foods have vastly improved overall data quality in the database. The NFNAP sampling approach was updated in 2001 using 2000 US Census data and recently updated to use 2010 Census population estimates. This design, like the 2001 design, employs a three-stage, stratified, probability-proportional-to-size (PPS) sample selection process; 1) county selection (based on population density); 2) supermarket outlets within selected counties (based on annual sales); and 3) specific brands of foods (based on market share data). In the first stage, Census regions (4), divisions and states were used to obtain a self-weighting sample of population centres, ensuring geographic dispersion across the 48 conterminous states; 48 locations were selected, with nested subsets of 24, 12 and 6 locations. Due to demographic changes in the population and congressional redistricting it was necessary to revise the sampling scheme to reflect these changes. With the increased penetration of warehouse-type retail outlets into the grocery industry, the sampling frame must be adjusted to include these purchase locations. Food samples which are collected nationally according to a statistically rigorous sampling approach are consistent with national representativeness and allow better estimates of the mean and variability than convenience sampling or less rigorous options.
ADDITIONAL INDEX WORDS. organic conventional comparison, phytochemicals, human nutrition and health, environmental effects SUMMARY. Demand for organically grown produce is increasing, largely due to concerns of consumers about health and nutrition. Previous studies have not shown a consistent difference of essential nutrients, such as vitamins and miner-als, between organic food crops and the conventional counterparts. However, to date, little consideration has been given to phytochemicals, secondary plant metabolites with potential health-promoting properties. We fi rst discuss factors that can infl uence the levels of phytochemicals in crops, and then we critically review the results of published studies that have compared the effects of organic and conventional production systems on phytochemical contents of fruit and vegetables. The evidence overall seems in favor of enhancement of phytochemical content in organically grown produce, but there has been little systematic study of the factors that may contribute to increased phytochemical content in organic crops. It remains to be seen whether consistent differences will be found, and the extent to which biotic and abiotic stresses, and other factors such as soil biol-ogy, contribute to those differences. Problems associated with most studies tend to weaken the validity of comparisons. Given the limitations of most published studies, needs for future research are discussed. Work supported in part by a grant from the Organic Farming Research Foundation for a project entitled "Are organic vegetables more nutritious?" and by Initiative for Future Agriculture and Food Systems Grant No. 2001-52101-11431 from the USDA Cooperative State Research, Education, and Extension Service. Contribution #05-295-J of the Kansas Agricultural Experiment Station. Acknowledgment: We gratefully thank Mary B. Kirkham for reviewing this manuscript and providing helpful suggestions.
Current experiment was laid out in order to compare different kinds of organic manure and chemical fertilizer application in growing spinach under the open-field conditions in two successive seasons. Matador type spinach (Spinacea oleracea L.) was cultivated organically and conventionally and spinach growth, yield, vitamin C and nitrate concentrations were checked throughout two successive seasons (autumn and winter). Commercial chemical fertilizer was used as conventional application, and chicken manure (CM), farmyard manure (FM) and blood meal (BM) were used as organic manure applications as a single and as mixtures at different quantities by aiming to receive 150kgNha−1 for each, totally 19 applications. In general, autumn season gave the better results in terms of spinach growth, yield and resulted in lower nitrate concentration, whereas the vitamin C concentration was found to be higher in winter season. Reasonable applications to be recommended should be as follows with regard to the seasons; 3.5tonha−1 CM and 0.6tonha−1 BM+0.85tonha−1 CM+4.0tonha−1 FM for spinach growth; 3.5tonha−1 CM and 5.0 FM+1.2 CM+0.4 BM applications for spinach yield; 5.0tonha−1 FM+2.5tonha−1 CM and 15.0tonha−1 FM for vitamin C and nitrate concentration in the autumn and the winter season, respectively. In conclusion, FM and CM can be used effectively in growing organic spinach especially in the autumn season and can be transferred successfully into an asset.
Objective.
—To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults.
Organic and conventional crop management systems differ in terms of the fertilisers and plant protection methods used. Ecological and agronomic research on the effect of fertilization on plant composition shows that increasing availability of plant available nitrogen reduces the accumulation of defense-related secondary metabolites and vitamin C, while the contents of secondary metabolites such as carotenes that are not involved in defense against diseases and pests may increase. In relation to human health, increased intake of fruits and vegetables is linked to reduced risk of cancer and cardiovascular disease. This benefit may be primarily due to their content of defense-related secondary metabolites, since most other constituents of fruits and vegetables either are not unique to these foods or have been shown to not provide health benefits when the intake is increased. A meta-analysis of the published comparisons of the content of secondary metabolites and vitamins in organically and conventionally produced fruits and vegetables showed that in organic produce the content of secondary metabolites is 12% higher than in corresponding conventional samples (P < 0.0001). This overall difference spans a large variation among sub-groups of secondary metabolites, froma 16% higher content for defence-related compounds (P < 0.0001) to a nonsignificant 2% lower content for carotenoids, while vitamin C showed a 6% higher content (P = 0.006). Based on the assumption that increasing the content of biologically active compounds in fruits and vegetables by 12% would be equivalent to increasing the intake of fruits and vegetables by the same 12%, a model developed to calculate the health outcome of increasing the intake of fruits and vegetables was then used to tentatively estimate the potential increase in life expectancy that would be achieved by switching from conventional to organic produce without changing the amount consumed per day, to 17 days for women and 25 days for men.
Tomatoes (Solanum lycopersicum L.) are widely consumed and well known for their health benefits, many of which have been associated with the high levels of antioxidants present in tomatoes. With a growing interest in local and organic foods, it would be helpful to determine whether farmers could naturally improve the quality and antioxidant content of tomatoes for sale in local markets. This study evaluated antioxidant properties, quality attributes, and yield for 10 tomato cultivars grown for 2 years using certified organic and conventional practices.
Cultivar and year effects impacted (P < 0.05) all tests conducted, while growing method influenced (P < 0.05) yield, soluble solids content, ascorbic acid, and antioxidant radical scavenging capacity. Even when accounting for year-to-year variability, cultivars in the highest groups had 1.35- to 1.67-fold higher antioxidant levels than cultivars in the lowest groups. 'New Girl', 'Jet Star', 'Fantastic', and 'First Lady' were always in the highest groups, while 'Roma' and 'Early Girl' consistently had the lowest antioxidant content.
Compared to production practices and environmental effects of years that are generally beyond the control of small-scale producers, choice of cultivar provides the simplest and most effective means of increasing antioxidant properties. Knowledge of tomato cultivars with naturally higher antioxidant levels could assist smaller-scale producers to grow fruit that may provide a competitive advantage and the opportunity to capitalize on the increasing popularity of locally grown, high-quality fresh produce.
The effects of low-concentration electrolysed water (LcEW) (4 mg/L free available chlorine) combined with mild heat on the safety and quality of fresh organic broccoli (Brassica oleracea) were evaluated. Treatment with LcEW combined with mild heat (50 C) achieved the highest reduction in naturally occurring microorganisms and pathogens, including inoculated Escherichia coli O157:H7 and Listeria monocytogenes (P < 0.05). In terms of the antioxidant content of the treated broccoli, the total phenolic levels and ferric reducing antioxidant power remained unchanged; however, the oxygen radical absor-bance capacity of the treated broccoli was higher than that of the untreated control. In addition, mild heat treatment resulted in an increase in firmness. The increased firmness was attributed to changes in the pectin structure, including the assembly and dynamics of pectin. The results revealed that mild heat induced an antiparallel orientation and spontaneous aggregation of the pectin chains. This study demonstrated that LcEW combined with mild heat treatment was effective to reduce microbial counts on fresh organic broccoli without compromising the product quality.
The Brazilian Society of Nutrition, through the present public ation, brings to the attention of the world scientific community the works presented at the XI INTERNATIONAL CONGRESS OF NUTRITION which, promoted by this Society and under the sponsorship of the Interna tional Union of Nutritional Science, was held in the city of Rio de Janeiro from August 27th to September lst, 1978. The publication, edited by Plenum Publishing Corporation, is 11 titled Nutrition and Food Science: Presented Knowledge and Utiliza tion•• and appears in three volumes. under the following titles and sub-titles: Vol. I - FOOD AND NUTRITION POLICIES AND PROGRAMS - Planning and Implementation of National Programs - The role of International and Non-governmental Agencies - The role of the Private Sector -Program Evaluation and Nutritional Surveillance - Nutrition Intervention Programs for Rural and UrbanAreas - Mass Feeding Programs - Consumer Protection Programs Vol. I I -NUTRITION EDUCATION AND FOOD SCIENCE AND TECHNOLOGY - Animal and Vegetable Resources for Human Feeding - Food Science and Technology - Research in Food and Nutrition - Nutrition Education Vol. I I I -NUTRITIONAL BIOCHEMISlRY AND PATHOLOGY - Nutritional Biochemistry - Pathological and Chemical Nutrition - Nutrition, Growth and Human Development v vi FOREWORD It is hoped that this publication may prove useful to all those who are tnterested in the different aspects of Nutrition Science. Editorial Committee: Walter J. Santos J. J.
The effects of low-concentration electrolysed water (LcEW) (4 mg/L free available chlorine) combined with mild heat on the safety and quality of fresh organic broccoli (Brassica oleracea) were evaluated. Treatment with LcEW combined with mild heat (50 C) achieved the highest reduction in naturally occurring microorganisms and pathogens, including inoculated Escherichia coli O157:H7 and Listeria monocytogenes (P < 0.05). In terms of the antioxidant content of the treated broccoli, the total phenolic levels and ferric reducing antioxidant power remained unchanged; however, the oxygen radical absor-bance capacity of the treated broccoli was higher than that of the untreated control. In addition, mild heat treatment resulted in an increase in firmness. The increased firmness was attributed to changes in the pectin structure, including the assembly and dynamics of pectin. The results revealed that mild heat induced an antiparallel orientation and spontaneous aggregation of the pectin chains. This study demonstrated that LcEW combined with mild heat treatment was effective to reduce microbial counts on fresh organic broccoli without compromising the product quality.
For nearly 20 years, the National Food and Nutrient Analysis Program (NFNAP) has expanded and improved the quantity and quality of data in US Department of Agriculture’s (USDA) food composition databases (FCDB) through the collection and analysis of nationally representative food samples. NFNAP employs statistically valid sampling plans, the Key Foods approach to identify and prioritize foods and nutrients, comprehensive quality control protocols, and analytical oversight to generate new and updated analytical data for food components. NFNAP has allowed the Nutrient Data Laboratory to keep up with the dynamic US food supply and emerging scientific research. Recently generated results for nationally representative food samples show marked changes compared to previous database values for selected nutrients. Monitoring changes in the composition of foods is critical in keeping FCDB up-to-date, so that they remain a vital tool in assessing the nutrient intake of national populations, as well as for providing dietary advice.
The Food and Drug Administration (FDA or we) is amending its labeling regulations for conventional foods and dietary supplements to provide updated nutrition information on the label to assist consumers in maintaining healthy dietary practices. The updated information is consistent with current data on the associations between nutrients and chronic diseases, health-related conditions, physiological endpoints, and/or maintaining a healthy dietary pattern that reflects current public health conditions in the United States, and corresponds to new information on consumer understanding and consumption patterns. The final rule updates the list of nutrients that are required or permitted to be declared; provides updated Daily Reference Values and Reference Daily Intake values that are based on current dietary recommendations from consensus reports; amends requirements for foods represented or purported to be specifically for children under the age of 4 years and pregnant and lactating women and establishes nutrient reference values specifically for these population subgroups; and revises the format and appearance of the Nutrition Facts label.
The contents of soluble sugars (sucrose, fructose, glucose, maltose and raffinose), vitamin C and free amino acids (34 compounds, essential and non-essential) were quantified in open-field and greenhouse-grown spinaches in response to cold stress using liquid chromatography. In general, greenhouse cultivation produced nutritionally high value spinach in a shorter growing period, where the soluble sugars, vitamin C and total amino acids concentrations, including essential were in larger amounts compared to those grown in open-field scenarios. Further, low temperature exposure of spinach during a shorter growth period resulted in the production of spinach with high sucrose, ascorbate, proline, gamma-amino butyric acid, valine and leucine content, and these constitute the most important energy/nutrient sources. In conclusion, cultivation of spinach in greenhouse at a low temperature (4-7 °C) and exposure for a shorter period (7-21 days) before harvest is recommended. This strategy will produce a high quality product that people can eat.
A wide range of nutrients and health-promoting non-nutrient components in mushrooms are a subject of international research, but specific reference materials to facilitate comparison of results among laboratories are lacking. Commercially available food matrix reference materials do not contain components unique to mushrooms (e.g., ergosterol, vitamin D2, chitin, beta-glucans, agaritine, ergothioneine). A Mixed Mushroom Control Material (CM) (homogeneous mixture of 15 types of mushrooms) was prepared and characterized for selected components, including proximates (moisture, protein, ash), total folate, folate vitamers, ergosterol, ergosterol metabolites, vitamin D2 (ergocalciferol), amino acids, total dietary fiber, agaritine, elements (sodium, potassium, phosphorous, magnesium, calcium, iron, copper, manganese, zinc), riboflavin, niacin, thiamin, vitamin B6, pantothenic acid. Subsamples of the CM are available to qualified laboratories from the Food Analysis Laboratory Control Center at Virginia Tech (Blacksburg, VA, USA), to be assayed concurrently with mushroom samples for which food composition data will be published along with results for the CM. Implementation of this CM should facilitate comparison of published data on mushroom composition and health benefit among species, and biodiversity within species by serving as common control sample that allows the separation of analytical variability from true differences in sample composition determined at different laboratories.
Ascorbic acid is a vitamin (vitamin C) for only a limited number of species: human beings and other primates, bats, the guinea pig, a number of birds, and teleost fishes.
Vitamin C loss was compared in homogenized raw broccoli, potatoes, spinach, strawberries, oranges, and tomatoes; baked potatoes; steamed broccoli and spinach; and pasteurized orange juice after storage under residual nitrogen under refrigeration, and frozen at conventional (-10 to -20. °C) and ultra-low (<-55. °C) temperatures for 1, 3, and 7 days. Additional foods (cantaloupe, green sweet peppers, collard greens, clementines) were monitored for 3-4 years at <-55. °C. Total ascorbic acid was quantified using high-performance liquid chromatography and detailed quality control measures. No decrease occurred in any of the foods after 7 days at <-55. °C. Under refrigeration the largest decreases were in raw spinach and broccoli, averaging (mg/100. g) 9.5 (29%) and 33.1 (29%), respectively, after 1 day and 31.0 and 77.0 after 7 days (94% and 68%, respectively). With conventional freezing, vitamin C was stable for 7 days in most of the products studied; minor losses occurred in raw spinach and broccoli after 1 day but were substantial after 3 days, 6.9. mg/100. g (23%) and 17.0. mg/100. g (15%), respectively; and 7 days (13.1 and 32.0. mg/100. g). For homogenates stored long-term at <-55. °C, vitamin C loss occurred in only cantaloupe, collard greens, and one sample of raw potatoes, all before 50 weeks.
Evidence of associations between single nutrients and head and neck cancer (HNC) is still more limited and less consistent than that for fruit and vegetables. However, clarification of the protective mechanisms of fruit and vegetables is important to our understanding of HNC etiology. We investigated the association between vitamin C intake from natural sources and cancer of the oral cavity/pharynx and larynx using individual-level pooled data from ten case-control studies (5,959 cases and 12,248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. After harmonization of study-specific exposure information via the residual method, adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional multiple logistic regression models on quintile categories of 'non-alcohol energy-adjusted' vitamin C intake. In the presence of heterogeneity of the estimated ORs among studies, we derived those estimates from generalized linear mixed models. Higher intakes of vitamin C were inversely related to oral and pharyngeal (OR = 0.54, 95% CI: 0.45-0.65, for the fifth quintile category versus the first one, p for trend<0.001) and laryngeal cancers (OR = 0.52, 95% CI: 0.40-0.68, p for trend = 0.006), although in the presence of heterogeneity among studies for both sites. Inverse associations were consistently observed for the anatomical subsites of oral and pharyngeal cancer, and across strata of age, sex, education, body mass index, tobacco, and alcohol, for both cancer sites. The inverse association of vitamin C intake from foods with HNC may reflect a protective effect on these cancers; however, we cannot rule out other explanations.
The levels of phytochemicals in organically and conventionally cultivated Meyer lemons (Citrus meyeri Tan.) are unknown. In this study, Meyer lemons grown in south Texas under similar climatic conditions, using organic and conventional cultivation practices, were evaluated for their levels of phytochemicals. Mature fruits were harvested in two seasons, stored at market-simulated post-harvest conditions for four weeks, and periodically evaluated for levels of phytochemicals, including flavonoids, amines, organic acids and minerals. Results indicate that organically grown lemons contain significantly (P ≤ 0.05) higher levels of hesperidin, didymin and ascorbic acid than those cultivated in conventional system. Phenolic content was higher in organic lemons, whereas levels of citric acid and amines were higher in conventionally cultivated lemons. These results suggest that organically grown Meyer lemons are a good source of enhanced levels of flavonoids and ascorbic acid. Furthermore, storage of fruits at 10 °C up to four weeks helps maintain the levels of phytochemicals. To the best of our knowledge, this is the first report of phytochemicals evaluation of organic and conventionally grown Meyer lemons.
Some studies suggest a favorable role of antioxidants on breast cancer risk but this is still inconclusive. The aim of this study was to assess whether overall dietary antioxidant capacity, as assessed by dietary ferric reducing antioxidant potential (FRAP), and individual dietary antioxidant intake were associated with breast cancer risk.Data was used from women participating in the Rotterdam Study, a prospective cohort study among subjects aged 55 years and older (N=3209). FRAP scores and antioxidant intake (i.e. vitamin A, C, E, selenium, flavonoids, and carotenoids) was assessed at baseline by a food frequency questionnaire. Incident cases of breast cancer were confirmed through medical reports.During a median follow-up of 17 years, 199 cases with breast cancer were identified. High dietary FRAP score was associated with a lower risk of breast cancer (HR: 0.68; 95% CI: 0.49, 0.96). No overall association between individual antioxidant intake and breast cancer risk was found. However, low intake of alpha carotene and beta carotene was associated with a higher risk of breast cancer among smokers (HR: 2.48; 95% CI: 1.21, 5.12 and HR: 2.31; 95% CI: 1.12, 4.76 for alpha and beta carotene respectively) and low intake of flavonoids was associated with breast cancer risk in women over the age of 70 (HR: 1.80; 95% CI: 1.09, 2.99). These results suggest that high overall dietary antioxidant capacity are associated with a lower risk of breast cancer. Individual effects of dietary carotenoids and dietary flavonoids may be restricted to subgroups such as smokers and elderly. © 2014 Wiley Periodicals, Inc.
Leaf green Brassica crops: collard (Brassica oleracea L.), mustard (Brassica juncea L.) and turnip (Brassica rapa L.) greens are important commercial and culinary vegetables, especially in the southern United States. However, almost no information on essential human-health vitamins [ascorbic acid (vitamin C), folate (vitamin B9), phylloquinone (vitamin K1) and the carotenoids lutein and β-carotene (provitamin A)] is available. Leafy green Brassicas (15 collard, 2 mustard and 2 turnip greens) were harvested at peak whole-plant maturity, separated into younger (top-canopy) or older (bottom-canopy) leaves and assayed for the aforementioned vitamins and carotenoids. On a 100 g fresh mass basis, percent dry mass (14.7 g versus 13.2 g), total (132.7 mg versus 109.1 mg) and free (58.7 mg versus 52.8 mg) ascorbic acid, folate (183 μg versus 112 μg) and lutein (9790 μg versus 8950 μg) concentrations were significantly higher in younger versus older leaves. Phylloquinone (435 μg versus 459 μg) and β-carotene (11,130 μg versus 11,619 μg) were equally concentrated in younger and older leaves. On a fresh mass basis, all vitamins were found to be highly concentrated in all nineteen leafy green Brassica genotypes, with particular genotypes within each Brassica species having exceptionally high concentrations. Findings from this study revealed that leafy green Brassica genotypes are nutritionally dense in essential human-health vitamins C, B9, K, provitamin A (β-carotene) and lutein. Concentration differences in the examined nutritional components among the genotypes (e.g. significant differences in lutein concentrations from 5120 to 15,360 μg/100 gfm) reveal potential differences that might be exploited in genetic improvement through plant selection and breeding.
During the 1986 growing season, samples of seven potato cultivars from eight provinces in Canada were tested for vitamin C content. The seven cultivars were: Superior, Russett Burbank, Red Pontiac, Norchip, Shepody, Yukon Gold and Kennebec. The mean vitamin C for the cultivars ranged from 12.4–18.1 mg/100g potato, fresh weight. Variations in vitamin C were highly significant with respect to cultivar and location (P < 0.01). The cultivars, Yukon Gold and Shepody, contained the highest amounts of vitamin C. The present study was for one year. It is suggested that a much longer study period (3–5 year) is required to give a better estimate for nutrient data tables where use of a range of vitamin C, rather than a mean, may be more appropriate.RésuméUne enquête sur la teneur en vitamine C a porté sur des échantillons de sept cultivars de pomme de terre de huit provinces du Canada, durant la saison 1986. Les sept cultivars étaient: Supérieur, Russett Burbank, Red Pontiac, Norchip, Shepody, Yukon Gold, et Kennebec. La teneur moyenne en vitamine C a varié de 12.4 à 18.1 mg/100 g de pomme de terre, poids frais. Les variations en vitamine C furent fortement significatives (P < 0.01) par rapport au cultivar et à la localisation. Les cultivars Yukon Gold et Shepody furent les plus riches en vitamine C. L'étude courant n'a porté que sur une seule année. Il est suggéré qu'une période beaucoup plus longue (3–5 ans) est nécessaire pour obtenir un meilleur estimé pour les tableaux de données nutritionnelles où l'usage d'une marge de vitamine C est plus approprié qu'une moyenne.
We report on the application of supplementary light-emitting diode (LED) lighting within a greenhouse for cultivation of red, green and light green leaf baby lettuces (Lactuca sativa L.) grown under natural illumination and high-pressure sodium (HPS) lamps (16-h; PPFD-170 μmol m−2 s−1) during different growing season. Supplementary lighting from blue 455/470 nm and green 505/530 nm LEDs was applied (16-h; PPFD-30 μmol m−2 s−1). Our results showed that to achieve solely a positive effect is complicated, because metabolism of antioxidant properties in lettuce depended on multicomponent exposure of variety, light quality or seasonality. The general trend of a greater positive effect of supplemental LED components on the vitamin C and tocopherol contents was in order: 535 > 505 > 455 > 470 nm; on the total phenol content: 505 > 535 = 470 > 455 nm; on the DPPH free-radical scavenging capacity: 535 = 470 > 505 > 455 nm; on the total anthocyanins: 505 > 455 > 470 > 535 nm. Further investigations are needed for understanding the mechanism and interaction between antioxidants and light signal transduction pathways.
The purpose of this study was to evaluate the effects of processing, i.e. heating (98 °C, 10 min), freezing (−20 °C) and freeze-drying on anthocyanins, carotenoids, and vitamin C in summer fruits and vegetables, i.e. cherries, nectarines, apricots, peaches, plums, carrots and red bell peppers. The commodities were collected from growers located in the Otago region (namely Cromwell, Roxburgh, Mosgiel and Clinton), New Zealand. The results revealed that each commodity contained different contents of phytochemicals. The content and the process stability of phytochemicals in each commodity were influenced by the geographical location of the growers. In general, a high content of phytochemicals was found in summer fruits and vegetables grown in Otago compared to those grown in the Northern Hemisphere, e.g. anthocyanins in cherries, nectarines, peaches and plums; total carotenoids in red bell peppers and nectarines and vitamin C in cherries, peaches, red bell peppers and carrots. Heating and freezing enhanced the release of membrane bound anthocyanins, resulting in higher content after processing compared to fresh commodities. In the commodities studied, with the exception of red bell peppers, the stability of ascorbic acid was increased if ascorbic acid oxidase was inactivated for example by heating.
Phytochemicals are important natural bioactive compounds of fruit and vegetables and are widely recognised for their nutraceutical effects and health benefits. This review analyses different factors influencing the level of phytochemicals in selected fruit and vegetables at different processing stages in the production chain. The level of phytochemicals present in fruit and vegetables may vary within and across cultivars. Available literature correlates the level of phytochemicals with many factors including cultivar type, environmental and agronomic conditions, harvest and food processing operations, and storage factors. The optimisation of food processing and storage factors is an essential step to reduce the degradation of phytochemicals for potential health benefits. Cultivar selection and maturity at harvest may be critical for food processors to maintain high levels of phytochemicals in fruit and vegetables.
Nearly 90% of vitamin C in the human diet is obtained from fruits and vegetables as ascorbic and dehydroascorbic acids. However, these compounds are sensitive to light and oxygen and may decompose under normal transport and storage conditions, resulting in reduction of the nutritional value of the foodstuffs. In this work, the effect of various commercial and domestic storage conditions (3, 8, 23°C with or without light) on vitamin C contents of some fruits and vegetables produced in Quebec was studied. In general, degradation of vitamin C is a function of time. In some foodstuffs, however, the onset of degradation is delayed during the first few days during which the vitamin content actually increases as a result of continuing endogenous metabolism.
The Dietary Approaches to Stop Hypertension trial involved 4 clinical sites at which 459 participants (in 5 cohorts) were fed 3 dietary patterns over 11 weeks per cohort. The 3 patterns were a control diet, a fruits and vegetables diet, and a combination diet. Before the intervention, key nutrient levels in each diet were validated at 2 energy levels (2,100 and 3,100 kcal) by chemical analysis of the prepared menus. During intervention, diets were sampled across all cohorts, sites, and energy levels, and 7-day menu cycle composites were assayed. In general, sodium, potassium, calcium, and magnesium in the validated menus for each diet/energy level met the nutrient targets, though moderate variability was evident among individual menus, particularly for potassium, calcium, and magnesium. However, as intended, there was clear separation and no overlap in mineral levels in individual menus of diets that were designed to differ. During intervention, macronutrient contents met nutrient goals. Sodium, potassium, calcium, and magnesium in the diets generally met target levels, though potassium in the fruits and vegetables diet was 11% to 23% below target. There were no consistent differences in nutrient levels between sites. The mean nutrient levels in the validated menus and diets sampled during intervention were in excellent agreement with each other, though sodium was somewhat higher (∼6%) in the diets from intervention vs validation. These results indicate the success of the quality control measures implemented and suggested consistent overall diet composition throughout the 28 months during which the study was conducted. J Am Diet Assoc. 1999;99(suppl): S60–S68.
Lettuce (Lactuca sativa L.) is a major food crop within the European Union. The objective of this study was to test the potential nutritional quality of three types of lettuce consumed as salads: Lactuca sativa L. var. longifolia (commonly named Cogollos de Tudela) and two cultivars of Lactuca sativa L. var. capitata (Batavia Rubia Munguía and Maravilla de Verano). Distribution of sugars, proteins, minerals and antioxidant compounds (carotenoids, chlorophylls, phenolics, anthocyanins and ascorbate) between outer and inner leaves was tested. The potential benefits of each variety or cultivar were due to different compounds accumulated in leaves. Cogollos de Tudela showed higher levels of Mg and Ca in both external and internal leaves, and greater concentrations of Mn, chlorophylls and carotenoids in inner leaves than lettuces belonging to the var. capitata. Batavia Rubia Munguía had low quantity of Na and an important amount of K, Mg, Ca, Fe and Zn in outer leaves and it was the cultivar that accumulated the highest quantity of water in both outer and inner leaves. Maravilla de Verano showed the greatest contents of anthocyanins and ascorbate in external leaves. In the three cultivars some of the potentially beneficial compounds appeared in higher levels in the outer than in the inner leaves. Therefore, the complete elimination of the external leaves should be reconsidered when lettuces are consumed as salads or used as food crop for the ‘Fourth Range’ of vegetables.
Vitamin C, assayed as total ascorbic acid (AA), was extracted from foods using HPLC with ultraviolet spectrophotometric detection, including treatment of the extract tris(2-carboxyethyl) phosphine (TCEP) to reduce any dehydroascorbic acid to AA. The method was validated for a variety of matrices including fruits and vegetables, fruit juice, dried spices, and high-starch and high-fat foods, using spike recovery, sequential extractions, analysis of available certified reference materials, and verification of AA peak purity. The limits of detection and quantitation were 0.06–0.09 mg and 0.2 mg AA per 100 g food, respectively. The average recovery of added AA from all matrices was 97–103%.The inter-day relative standard deviation (RSD) for matrices including orange juice, fortified cereal, a fruit and vegetable composite, and freeze-dried vegetables was 1.1–2.0% and 4.8%, and HORRAT values (RSD/predicted RSD) for a wide range of foods were <0.1–0.6. Results for certified reference materials, BCR®431 (freeze-dried Brussels sprouts), BCR®421 (milk powder) and VMA399 (dry breakfast cereal) (465 ± 4.6, 74.0 ± 1.1 and 70.5 ± 1.5 mg/100 g, respectively) were within the certified ranges. Without matrix-specific method adjustments to the method validated for orange juice, extraction problems and interferences in the AA peak for particular matrices lead to over- or underestimation of vitamin C in many foods (0.3–70 mg/100 g; 5.5–64%).
L-Ascorbic acid, commonly known as vitamin C is well-known in chemistry since long back. It has tremendous medical applications in several diseases. However, application of this chiral molecule in organic synthesis has been neglected earlier. In the later part of twentieth century application of ascorbic acid has gained momentum in organic synthesis of different molecules of biological importance and of chemotherapeutic significance. We have given an account of the history, chemistry, biochemistry and biosynthesis of ascorbic acid and application of this small molecule in organic synthesis. The application of ascorbic acid in accessing chiral synthons has also been described.
Activities and some other properties of ascorbate oxidases (AAO) from the fruits of family Cucurbitaceae were investigated. The peel and the flesh of seven varieties had activities ranging between 35–56500 units/mg protein and 14–1250 units/mg protein, respectively. AAO from different varieties had a similar pH optimum of around 6–6.5 and a broad pH stability ranging from pH 5 or 6 to pH 10 or 11. These properties appear to be conserved in the AAO's from the family of Cucurbitaceae. The AAO's of melon cv. andes, kinsho and papaya were more susceptible to heat denaturation than AAO from pumpkin.
This review is concerned with the summary and evaluation of the results from more than 150 investigations comparing the quality of conventionally and organically produced food or of foods produced with the aid of different fertilisation systems. Cereals, potatoes, vegetables, fruits, wine, beer, bread, cakes and pastries, milk, meat, eggs and honey, as well as products made from them, have been included in the review. Most of the studies evaluated are physico-chemical investigations of concentrations of desirable and undesirable ingredients, pesticide residues, contaminants, sensory analyses and feed experiments with animals. Nutritional studies in humans and experiments which used holistic methods of analysis are also included. Since different methods of sampling were used in the investigations, a summary evaluation of individual results is extremely difficult. Even when the sampling methods are of the same type, a great many factors have to be taken into consideration which are not directly related to the production system but which do influence food quality to a large degree. Despite the heterogeneity of the sample material, some differences in quality between products from conventional and organic farming or foods produced with the aid of different fertilisation systems have been identified. © 1997 SCI
To investigate the variations in quality with growth stage and postharvest storage, spinach was sown on three occasions. For each occasion, the spinach was harvested at three growth stages at 6-day intervals. The second stage corresponded to a growth period used for baby spinach by commercial growers. After harvest, the leaves were stored in polypropylene bags at 2 °C or 10 °C. The highest ascorbic acid content in fresh material was found at stage I. During storage, the ascorbic acid content decreased considerably and the dehydroascorbic acid/vitamin C ratio increased. Storage at 2 °C gave a smaller reduction in ascorbic acid content than storage at 10 °C. Total carotenoid content increased or remained stable during storage. Lutein was the major carotenoid, making up about 39% of the total carotenoid content, followed by violaxanthin, β-carotene and neoxanthin. Visual quality decreased during storage in most cases, and was correlated to initial ascorbic acid and dry matter contents. The initial AA content might therefore be used as a parameter for predicting the shelf-life of baby spinach. The results also indicate that by harvesting baby spinach a few days earlier than the current commercial stage of harvest the postharvest visual quality and nutritional quality may be improved. Copyright © 2005 Society of Chemical Industry
An experiment was conducted for three years in a Pugwash sandy loam near Truro, NS. Five replicates of two treatments (organic and conventional) were established annually in different plot areas for potatoes (Solanum tuberosum L. Superior) and sweet corn (Zea mays L. var. saccharata `Sunnyvee' or `Pride and Joy'. The addition of pesticides, lime and NPK fertilizer to the conventional plots followed a soil test and provincial recommendations; lime, composted manure and insect control applications to the organic plots were according to the guidelines of the OCIA [Organic Crop Improvement Association, 1990. OCIA Certification Standards. OCIA, Bellefontaine, OH, 11 pp.] The compost was analysed for total N and applied to provide 260 kg N/ha for potatoes and 200 kg N/ha for sweet corn, which assumed 50% availability of the total N. Marketable yields were determined, and potato leaves and tubers, as well as sweet corn kernels and ear leaves were digested and analysed for 12 macro- and micronutrients. In addition, the vitamin C content of the tubers and the vitamin C and E contents of the kernels were analysed. Soil samples were also taken at harvest and analysed for essential nutrients and available N. Analysis of the three years of data showed that the yield and vitamin C content of the potatoes was not affected by treatments. However, the conventionally grown treatment outproduced the organically grown treatment for Pride and Joy (cv.) corn, but there was no difference between treatments in the yield of Sunnyvee (cv.) corn or the vitamin C or E contents of the kernels in any year. At p<0.11, four elements in potato tubers (P, Mg, Na, Mn) and four elements in potato leaves (N, Mg, Fe, B) were influenced by treatments, but only leaf Cu was affected in the sweet corn. Correspondingly, extractable P, Ca, Mg and Cu were higher in organically fertilized potato plots; only extractable Mg was affected by treatments in the sweet corn, with the Mg content higher in the organic plots. Only leaf P and K were significantly positively correlated with extractable P (r=0.70) and K (r=0.73) in the potato plots, while leaf Cu and kernel S were positively correlated with extractable Cu (r=0.56) and S (r=0.62) in the sweet corn plots.
The National Food and Nutrient Analysis Program (NFNAP) was designed in 1997 to develop robust and nationally representative estimates of the mean nutrient content of important foods in the food supply and significantly improve the quality of food composition data in the US Department of Agriculture's National Nutrient Databank. The underlying aims defining the process behind the NFNAP are: (1) evaluation of existing data; (2) identification of Key Foods and nutrients for analysis; (3) development of nationally based sampling plans; (4) analysis of samples; and (5) compilation and calculation of representative food composition data. Supported by a self-weighting stratified sampling design, the NFNAP approach has been applied to other sampling programs for the analysis of specific nutrients (e.g., fluoride-containing beverages and foods) and ethnic foods (e.g., American Indian foods). For select nutrients of potential health significance, additional sampling approaches allow for the estimation of serving-to-serving variability (e.g., highly processed foods). Under NFNAP, over 500 foods of the targeted 1000 important foods in the US food supply have been analyzed. Unrivaled research on food sampling, sample handling, and analytical methodology (e.g., for study of perishable nutrients in fresh produce) is integral to this effort. The NFNAP data are current, reflective of the market and nationally representative of the US food supply and therefore a crucial resource to health researchers, architects of nutrition policy, the nutrition and medical communities, and the food industry. They are released through the Web site: www.nal.usda.gov/fnic/foodcomp
The United States Department of Agriculture's (USDA) National Food and Nutrient Analysis Program (NFNAP) was initiated to update existing component values and to add data on new foods and components to reflect today's marketplace and needs for data. The USDA Nutrient Database for Standard Reference contains data for about 6040 foods for over 100 compounds. To develop a full nutrient profile for each food costs approximately $12 000 (six analytical samples×$2000 per sample). To determine food sampling priorities, the Nutrient Data Laboratory (NDL) has used the Key Foods approach to generate a list of 666 foods. This method utilizes existing nutrient profiles and nationally representative food consumption survey data collected by USDA in the Continuing Survey of Food Intakes by Individuals 1994–1996 (CSFII) and by The U.S. Department of Health and Human Services (USDHHS) in the National Health and Nutrition Examination Survey (NHANES). One premise of the project is that more samples will be collected and prepared for those foods which provide important amounts of nutrients of public health significance to the diet and not every sample will be analyzed for all the nutrients currently in NDL's nutrient databases. Even though the list of 666 Key Foods is much more manageable, procedures to set priorities for analysis are still needed. To accomplish this, two approaches were developed. One is based on a point system, and the other on nutrient consumption data. Based on an analysis of the two approaches, the nutrient consumption approach was chosen to be the primary method of selecting foods for analysis. This paper reports details of the two methods to modify the existing Key Foods list to determine new and specific priorities for NFNAP efforts. This program represents a comprehensive approach to collect baseline nationally representative data. Results will be used to update the USDA Nutrient Database for Standard Reference and to establish future priorities for frequency of updates.
Vitamin C, including ascorbic acid and dehydroascorbic acid, is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. The content of vitamin C in fruits and vegetables can be influenced by various factors such as genotypic differences, preharvest climatic conditions and cultural practices, maturity and harvesting methods, and postharvest handling procedures. The higher the intensity of light during the growing season, the greater is vitamin C content in plant tissues. Nitrogen fertilizers at high rates tend to decrease the vitamin C content in many fruits and vegetables. Vitamin C content of many crops can be increased with less frequent irrigation. Temperature management after harvest is the most important factor to maintain vitamin C of fruits and vegetables; losses are accelerated at higher temperatures and with longer storage durations. However, some chilling sensitive crops show more losses in vitamin C at lower temperatures. Conditions favorable to water loss after harvest result in a rapid loss of vitamin C especially in leafy vegetables. The retention of vitamin C is lowered by bruising, and other mechanical injuries, and by excessive trimming. Irradiation at low doses (1 kGy or lower) has no significant effects on vitamin C content of fruits and vegetables. The loss of vitamin C after harvest can be reduced by storing fruits and vegetables in reduced O2 and/or up to 10% CO2 atmospheres; higher CO2 levels can accelerate vitamin C loss. Vitamin C of produce is also subject to degradation during processing and cooking. Electromagnetic energy seems to have advantages over conventional heating by reduction of process times, energy, and water usage. Blanching reduces the vitamin C content during processing, but limits further decreases during the frozen-storage of horticultural products.
The National Food and Nutrient Analysis Program (NFNAP) is designed to develop robust estimates of the mean nutrient content of important foods in the food supply and significantly improve the quality of food composition data in the US Department of Agriculture's (USDA) National Nutrient Databank. The program objectives are: (1) evaluation of existing data; (2) identification of Key Foods and nutrients for analysis; (3) development of nationally based sampling plans; (4) analysis of samples; and (5) compilation and calculation of representative food composition data. This paper describes our efforts in development of the sampling plan (objective 3) and presents limited preliminary results. The sampling plan was based on a self-weighting stratified design. First, the U.S. was divided into four regions, then each region was further divided into three implicit strata from which generalized Consolidated Metropolitan Statistical Areas (gCMSAs) were selected. Rural and urban locations were selected within gCMSAs. Commercial supermarket lists were used to select 24 outlets for food pickups; specific brands were selected based on current market share data (pounds consumed). This population-based approach can be applied in the development of other sampling programs for specific ethnic and regional foods. Sampling plans have been developed for margarine, folate-fortified foods (e.g. flours, bread, and pasta), and a number of highly consumed mixed dishes (e.g. pizza and lasagna).
This study was undertaken to compare the levels of ascorbic acid, vitamin C, flavonoids, nitrate, and oxalate in 27 spinach varieties grown in certified organic and conventional cropping systems. Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-(ESI)MS/MS) of methanolic extracts of spinach demonstrated 17 flavonoids, including glucuronides and acylated di- and triglycosides of methylated and methylenedioxyderivatives of 6-oxygenated flavonoids. The mean levels of ascorbic acid and flavonoids were significantly (p < 0.001) higher in the organically grown [40.48 ± 6.16 and 2.83 ± 0.03 mg/kg of fresh weight (FW)] spinach compared to the conventionally grown spinach (25.75 ± 6.12 and 2.27 ± 0.02 mg/kg of FW). Conversely, the mean levels of nitrate were significantly (p < 0.001) higher in the conventionally grown spinach compared to the organically grown spinach. No significant effects were observed in the oxalate content of spinach from either production system. The levels of nitrate correlated negatively with those of ascorbic acid, vitamin C, and total flavonoids and showed a positive correlation with the oxalate content. These results suggest that organic cropping systems result in spinach with lower levels of nitrates and higher levels of flavonoids and ascorbic acid.
The National Food and Nutrient Analysis Program (NFNAP) was implemented in 1997 to update and improve the quality of food composition data maintained by the United States Department of Agriculture (USDA). NFNAP was designed to sample and analyze frequently consumed foods in the U.S. food supply using statistically rigorous sampling plans, established sample handling procedures, and qualified analytical laboratories. Methods for careful handling of food samples from acquisition to analysis were developed to ensure the integrity of the samples and subsequent generation of accurate nutrient values. The infrastructure of NFNAP, under which over 1500 foods have been sampled, mandates tested sample handling protocols for a wide variety of foods. The majority of these foods were categorized into several major areas: 1) frozen foods; 2) fresh produce and/or highly perishable foods requiring refrigeration; 3) fast foods and prepared foods; 4) shelf-stable foods; 5) specialized study and non-retail (point of production) foods; and 6) foods from remote areas (e.g. American Indian reservations). This paper describes the sample handling approaches, from the collection and receipt of the food items to the preparation of the analytical samples, with emphasis on the strategies developed for those foods. It provides a foundation for developing sample handling protocols of foods to be analyzed under NFNAP and for other researchers working on similar projects.
Retention of vitamin C in homogenized raw fruits and vegetables stored under routine conditions prior to analysis was investigated. Raw collard greens (Brassica oleracea var. viridis), clementines (Citrus clementina hort. ex Tanaka), and potatoes (Solanum tuberosum) were chosen, being representative of foods to be sampled in USDA's National Food and Nutrient Analysis Program (NFNAP), and having different expected stability of ascorbic acid (AA). Samples were homogenized in liquid nitrogen, assayed immediately, then stored at −60 °C and analyzed at time points up to 49 weeks. Vitamin C (as total AA after reduction of dehydroascorbic acid) was analyzed using a validated method with quantitation by HPLC/ultraviolet detection. An orange juice control sample was included in each run. Vitamin C concentrations were stable in clementines and the orange juice, but decreased in collards and potatoes [16.8 and 10.9 mg/100 g (14.7% and 30.4%), respectively, after 49 weeks]. Significant losses had occurred after 12 weeks. These results suggest similar matrices must receive careful attention to sample handling protocols before analysis or AA values may not reflect the concentration in the food as consumed. The control sample was critical to allowing assessment of storage effects independent of analytical variability. Fruits and vegetables for the NFNAP will be analyzed without storage until a practical stabilization protocol is validated.
The multi-billion dollar organic food industry is fueled by consumer perception that organic food is healthier (greater nutritional value and fewer toxic chemicals). Studies of the nutrient content in organic foods vary in results due to differences in the ground cover and maturity of the organic farming operation. Nutrient content also varies from farmer to farmer and year to year. However, reviews of multiple studies show that organic varieties do provide significantly greater levels of vitamin C, iron, magnesium, and phosphorus than non-organic varieties of the same foods. While being higher in these nutrients, they are also significantly lower in nitrates and pesticide residues. In addition, with the exception of wheat, oats, and wine, organic foods typically provide greater levels of a number of important antioxidant phytochemicals (anthocyanins, flavonoids, and carotenoids). Although in vitro studies of organic fruits and vegetables consistently demonstrate that organic foods have greater antioxidant activity, are more potent suppressors of the mutagenic action of toxic compounds, and inhibit the proliferation of certain cancer cell lines, in vivo studies of antioxidant activity in humans have failed to demonstrate additional benefit. Clear health benefits from consuming organic dairy products have been demonstrated in regard to allergic dermatitis.
The National Food and Nutrient Analysis Program (NFNAP) was designed to expand the quantity and improve the quality of data in the United States Department of Agriculture (USDA) food composition databases through the collection and analysis of nationally representative samples of foods and beverages. This paper describes some of the findings from the NFNAP and its impact on the food composition databases produced by USDA. The NFNAP employs statistically valid sampling plans, comprehensive quality control, and USDA analytical oversight as part of the program to generate new and updated analytical data for food components. USDA food consumption and composition data were used to target those foods that are major contributors of nutrients of public health significance to the U.S. diet (454 Key Foods). Foods were ranked using a scoring system, divided into quartiles, and reviewed to determine the impact of changes in their composition compared to historical values. Foods were purchased from several types of locations, such as retail outlets and fast food restaurants in different geographic areas as determined by the sampling plan, then composited and sent for analysis to commercial laboratories and cooperators, along with quality control materials. Comparisons were made to assess differences between new NFNAP means generated from original analytical data and historical means. Recently generated results for nationally representative food samples show marked changes compared to database values for selected nutrients from unknown or non-representative sampling. A number of changes were observed in many high consumption foods, e.g. the vitamin A value for cooked carrots decreased from 1,225 to 860 RAE/100g; the fat value for fast food French fried potatoes increased by 13% (14.08 to 17.06 g/100g). Trans fatty acids in margarine have decreased as companies reformulate their products in response to the required addition of trans fatty acids content on the nutrition label. Values decreased from 19.7 g/100 in 2002 to 14.8 g/100 in 2006 for 80%-fat stick margarines and to 4.52 g/100 g for 80%-fat tub margarines. These changes reflect improved strategies for sampling and analysis of representative food samples, which enhance the reliability of nutrient estimates for Key Foods and subsequent assessments of nutrient intake.