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Maximizing the Nutritional Value of Fruits & Vegetables
Abstract
A review commissioned by the Canned Food Alliance and prepared by faculty of the University of California Center for Excellence in Fruit & Vegetable Quality, has revealed that fruits & vegetables are a major source of macronutrients such as minerals and vitamin C, thiamin, riboflavin, B-6, A, and E. Most fruits & vegetables comprise 70-90% water and once separated from their source of nutrients undergo higher rates of respiration, resulting in moisture loss, quality and nutrient degradation, and potential microbial spoilage. Temperature and relative humidity should be carefully controlled to during harvesting and transportation of fruits & vegetables to maintain low rates of respiration, prevent moisture loss and maintain eating quality. Fruits & vegetables should be consumed soon after harvest, or postharvest handling condition should be controlled such that nutrient degradation does not occur.
... As or more important than greenhouse gas emissions incurred when fruit must travel long distances to reach the point of consumption are the nutrients lost between harvest and consumption. Fruits and vegetables typically contain over 90% water and once they are harvested, respiration rates increase, moisture decreases, and fruit quality degrades rapidly [4]. While refrigeration can slow down respiration processes and allow for longer shelf lives, nutrients inevitably degrade with time after harvest [4]. ...
... Fruits and vegetables typically contain over 90% water and once they are harvested, respiration rates increase, moisture decreases, and fruit quality degrades rapidly [4]. While refrigeration can slow down respiration processes and allow for longer shelf lives, nutrients inevitably degrade with time after harvest [4]. Of all nutrients lost with storage or transport of fresh fruit and vegetables, post-harvest decreases in vitamin C are the most dramatic, but riboflavin, folic acid, pantothenic acid, and biotin are also highly sensitive to post-harvest conditions and decline with increased temperatures and storage times [5]. ...
... Available commercially as benchtop (laboratory) equipment.3 Research; no commercial version available.4 Measured for gases only; RI range is not matched to liquid sensing applications. ...
Farm-to-table operations produce, transport, and deliver produce to consumers in very different ways than conventional, corporate-scale agriculture operations. As a result, the time it takes to get a freshly picked fruit to the consumer is relatively short and the expectations of the consumer for freshness and quality are high. Since many of these operations involve small farms and small businesses, resources to deploy sensors and instruments for monitoring quality are scarce compared to larger operations. Within stringent power, cost, and size constraints, this article analyzes chemical sensor technologies suitable for monitoring fruit quality from the point of harvest to consumption in farm-to-table operations. Approaches to measuring sweetness (sugar content), acidity (pH), and ethylene gas are emphasized. Not surprisingly, many instruments developed for laboratory use or larger-scale operations are not suitable for farm-to-table operations. However, there are many opportunities still available to adapt pH, sugar, and ethylene sensing to the unique needs of localized farm-to-table operations that can help these operations survive and expand well into the future.
... Fruits and vegetables are often most attractive and nutritious when harvested at their peak maturity. At retail stores, fruits and vegetables may spend one to three days on display prior to being purchased by the consumer, who may store them for up to seven days prior to consumption (Barrett 2007). Cold storage involves controlling the temperature in a storage room using mechanical refrigeration. ...
... (Giupu & Duo 2008). Most perishable commodities, however, are stored under refrigerated conditions, and storage life may range from eight to ten days for highly perishable fruits like berries to eight to ten weeks for less-perishable commodities like squash, pumpkin, apples, grapes and pears (Barrett 2007). Soluble sugars in fruits are mainly represented by sucrose, fructose and glucose, whilst malic, citric, and tartaric acids are the primary organic acids (Mahmood et al. 2012). ...
... Therefore, its content decreases during storage, particularly in conditions of high oxygen concentration (Roth et al. 2007). Most fresh fruits are acidic with a pH range from 3 to 5. (Barrett 2007). Citric acid (CA) is extensively used in the food, dairy, pharmaceutical, cosmetics, agricultural, and biochemical industries, among others (Dhillon et al. 2010). ...
Apples are a source of sugars, acids, and various biologically active compounds, such as phenolic compounds, which are responsible for most of the antioxidant activities of the fruit. The aim of this study was to evaluate how the cold storage of apple fruits affects the nutritional composition of selected organic acid and sugar content in juice in comparison to juice from fresh fruits. Statistical differences were confirmed between the content of citric acid, malic acid, total acid, pH, sucrose, fructose and glucose in juice from fresh fruits and from juice stored for 140 days. No statistical differences were observed between juice from fresh fruit and juice from fruits stored for 140 days in the content of acetic acid, tartaric acid, total sugar and sweetness index.
... Fruits and vegetables are a rich source of dietary fiber and micronutrients such as vitamin C, thiamin, riboflavin, B-6, niacin, folate, A, and E. Phytochemicals in fruits and vegetables, such as polyphenolics, carotenoids, and glucosinolates, may also have nutritional value [5]; [6]. Leafy vegetables deteriorate very rapidly after harvest and therefore require proper postharvest handling to preserve the quality at harvest. ...
... As part of the Malabo Declaration, African Union member states have committed to decreasing post-harvest food losses by 2025 [22]. Reduced post-harvest food losses have ramifications for other SDGs connected to food systems, as well as socioeconomic and environmental repercussions on SDGs 1,2,5,6,7,8,9,10,11,13,14,15, and 17 [23]; [3]. Fruit and vegetable post-harvest losses are difficult to anticipate; the major causes of spoiling are physiological damage and the interactions of numerous species. ...
The effect of two different drying techniques (Sun drying at ambient temperature for 2 days, and oven drying at 65 o C for 4 hours, on the proximate, mineral composition, vitamin content and ant-nutrients of fluted pumpkin leaf were studied. The results obtained showed that oven drying technique had higher protein (21.75%), moisture (82.25%) and Ash (6.50). High levels of vitamins A (17.25mg/100), B 1 (2.35 mg/100g), and B 2 (2.17mg/100g) content were observed in sun-drying of fluted pumpkin leaf. Low levels of P (156.25 mg/100g), Na (405.45 mg/100g) and K (178.40 mg/100g), were observed in the sun-drying. Oven-dried fluted pumpkin leaf showed significant lower level of anti-nutrients contents of Tanins (1.34 mg/100g), saponin (61.35 mg/100g), oxalate (70.20 mg/100g), phyates (1.12 mg/100g) and Trpsin (22.50 mg/100g) and microbial count of total plate count (2.4 x 10 2 Cfu/g) and Yeast/Mold (1.4 x 10 1 Cfu/g). This work showed that oven-drying of fluted pumpkin could be the best method of preserving it without compromising on its quality.
... Interest in the nutritional value of fruits and vegetables has been increasing, in part because of recent findings on the high level of obesity and other diet-related health problems in children and in part because of increased federal support of programs funding consumption of fresh and processed fruit and vegetable products. (Barrett et al. 2007) [6] . ...
... Interest in the nutritional value of fruits and vegetables has been increasing, in part because of recent findings on the high level of obesity and other diet-related health problems in children and in part because of increased federal support of programs funding consumption of fresh and processed fruit and vegetable products. (Barrett et al. 2007) [6] . ...
... Since September 2017 Thailand has had a tax on sugary drinks and taxes on salty snacks are scheduled to begin in 2021. Barrett (2007) concentrates on considering vitamin c loss in transit. Nutrient loss in transit is difficult to consider as it depends on particular fruit and vegetables, on mode of transport, on whether the plant material is whole or cut, and how or if it has been treated pre-transit ( Barrett, 2007). ...
... Barrett (2007) concentrates on considering vitamin c loss in transit. Nutrient loss in transit is difficult to consider as it depends on particular fruit and vegetables, on mode of transport, on whether the plant material is whole or cut, and how or if it has been treated pre-transit ( Barrett, 2007). Vitamin c losses in vegetables stored at 4 degrees centigrade for seven days range from 15% for green peas to 77% for green beans. ...
... Assessment of cultivars would provide greater context for understanding FV consumption and allow for greater understanding of the importance of cultivars and associated nutrient content [10,11], which could influence the significance of findings of associations among FV consumption and health outcomes including nutrient intake. Another aspect of FV consumption which must be considered is consumption relative to seasonality, i.e., when FV are harvested and transported, which can lead to nutrient degradation over time [9]. Consumption of local, seasonal FV is one way to minimize nutrient degradation. ...
... Consumption of local, seasonal FV is one way to minimize nutrient degradation. Additionally, further studies should examine the differences in nutrient content comparing fresh, frozen, and canned FV, as few studies have done so [9]. ...
Adequate consumption of fruits and vegetables is critical for healthy growth and development. Less is known about fruit and vegetable variety, with variation in operationalization of variety. This review aims to identify currently available evidence operationalizing fruit and vegetable (FV) variety through a scoping review to summarize, compare, and critically evaluate the operationalization of variety. A secondary aim is to examine the implications of measuring FV variety and outcomes including dietary quality/nutrient intake. PubMed, Medline, PsycINFO were searched using the following criteria: (1) human study participants ages 2 years and above; (2) assessment of fruit variety consumption, vegetable variety consumption, or combined fruit and vegetable variety consumption; and (3) peer-reviewed publication available in the English language. Etiologic, intervention, and determinant studies were eligible to be included, and 47 studies met inclusion criteria. Differences in operationalization of variety were found. Findings included associations of FV variety with aspects of nutrient intake, dietary behaviors, lifestyle behaviors, and health outcomes. There were no studies that assessed conventionally grown produce vs. organic produce, and none of the included studies assessed cultivar. Nonstandard classification of fruit and vegetables, differences in fruit and vegetables grown in other countries, and the restriction to studies published in the English language may have excluded studies examining variety published in languages other than English. Operationalization of variety should be reported to allow one to explore comparability across studies, use national or international guidelines for greater comparability, associate variety with nutrient intake, and change variety behaviors via intervention.
... However, producing fresh and high-quality produce is a real challenge and therefore a luxury in many regions of the world. Losses of nutrients during storage of fruit and vegetables are substantial if they are not canned or frozen quickly (Barrett 2007;Rickman et al. 2007). Therefore, for large-scale systems, food processing should at least be considered to balance out any fluctuations between supply and demand and reduce food waste. ...
... Most urban dwellers around the world rely on the transport of foods over long distances to meet daily needs (Grewal and Grewal 2012). One of the major criticisms is thus the reliance on fossil fuels required to transport products over large distances (Barrett 2007). The issue of food miles directs focus on the distance that food is transported from the time of production to purchase by the end consumer (Mundler and Criner 2016). ...
As the world’s population grows, the demands for increased food production expand, and as the stresses on resources such as land, water and nutrients become ever greater, there is an urgent need to find alternative, sustainable and reliable methods to provide this food. The current strategies for supplying more produce are neither ecologically sound nor address the issues of the circular economy of reducing waste whilst meeting the WHO’s Millennium Development Goals of eradicating hunger and poverty by 2015. Aquaponics, a technology that integrates aquaculture and hydroponics, provides part of the solution. Although aquaponics has developed considerably over recent decades, there are a number of key issues that still need to be fully addressed, including the development of energy-efficient systems with optimized nutrient recycling and suitable pathogen controls. There is also a key issue of achieving profitability, which includes effective value chains and efficient supply chain management. Legislation, licensing and policy are also keys to the success of future aquaponics, as are the issues of education and research, which are discussed across this book.
... Fruits and vegetables are a rich source of dietary fiber and micronutrients such as vitamin C, thiamin, riboflavin, B-6, niacin, folate, A, and E. Phytochemicals in fruits and vegetables, such as polyphenolics, carotenoids, and glucosinolates, may also have nutritional value [1]. African leafy vegetables such as leafy amaranth have received great attention as a cheap and readily available source of micronutrients for lowincome rural communities [2]. ...
... In addition to deterioration and loss of physical component of quality, vitamin C which is a major micronutrient in vegetables is known to decline rapidly after harvest. Loss of vitamin C is often used as an indicator of quality deterioration during postharvest handling including transportation, storage, and processing because it is highly susceptible to chemical and enzymatic oxidation and is highly water soluble [1]. ...
Leafy vegetables are very highly perishable and must be utilized immediately after harvest. Their fast deterioration is attributed to various biological and environmental factors with temperature playing a central role. Evaporative cooling is a low-cost temporary storage technology that offers smallholder vegetable farmers an alternative to expensive cold rooms. The present study sought to determine the effectiveness of evaporative cooling using zero energy brick cooler (ZEBC) and evaporative charcoal cooler (ECC), to preserve the postharvest quality of leafy amaranth vegetables. Freshly harvested vegetables were separated into bundles weighing 300 grams and stored under ZEBC, ECC, and ambient room conditions (control). Real time changes in temperature and relative humidity (RH) as well as changes in quality attributes (physiological weight loss (PWL), wilting index, hue angle, and vitamin C) were determined during the storage period. The temperature difference between the ZEBC and ECC versus the ambient air ranged between 4 and 10°C. Significantly higher RH (80–100%) was recorded in both evaporative cooling chambers. At the end of storage, higher PWL (47.6%) was recorded at ambient room conditions compared to 10.5 and 6.7% under ZEBC and ECC, respectively. A rapid decline in vitamin C (51%) was reported in vegetables stored at ambient room conditions. Overall, there was better vegetable quality preservation under ECC and ZEBC.
... Mycologists have yet to integrate the abundant physiological, morphological, and biogeographic data available for hundreds of species into a unifying paradigm of fungal LDD. If comparisons are to be effective or relevant, the highly relative nature of the spatial scales involved must be explicitly acknowledged in any discussion of LDD (46). ...
... Modern transportation enables fungi-including fungal tissue that cannot independently disperse-to traverse continents in less than 24 hours. For instance, fruits and vegetables grown in North America typically spend a maximum of 5 days in intracontinental transit following harvest, and the transport time of produce grown in the Southern Hemisphere for U.S. consumption can take as little as a few days, depending on the mode of transportation (46). ...
Long-Distance Dispersal of Fungi, Page 1 of 2
Abstract
The relative degree to which organisms move is a process operating at multiple temporal and physical scales ( 1 ). In recent years dispersal has received a great deal of attention in fields ranging from mathematics and physics to ecology and molecular biology, but only a patchy framework exists to explain dispersal over very large distances. Modeling patterns of long-distance dispersal (LDD) among macroorganisms, ranging from vertebrates and flying insects to seed plants, appears tractable, but documenting the geographic distributions and dispersal dynamics of microscopic propagules and microbes presents multiple theoretical and methodological challenges ( 2 – 4 ). The majority of empirical research directly measuring the dispersal of microbes or microscopic propagules is restricted to relatively short distances, and tracking dispersal at greater spatial scales involves mathematical or genetic models, e.g., in studies of moss ( 5 – 9 ), ferns ( 10 – 13 ), bacteria ( 14 – 19 ), and fungi ( 19 – 23 ). However, fitting dispersal data (e.g., from the tracking of spore movement) to mathematical functions often over- or underestimates LDD and imprecisely describes the trajectory of spore movement across large distances ( 24 – 28 ). Inferences based on population genetics data capture rare instances of successful LDD but incompletely describe underlying demographic processes and typically cannot speak to mechanisms of LDD ( 1 ). Besides the limitations of mathematical and genetic methods, important details about the natural history of species are often ignored or remain unknown, leaving many questions unanswered, including, e.g., how ephemeral propagules remain viable while exposed to harsh environments over extended periods of time.
... They are also foods with low energy density that means they have few calories in relation to the volume of the food consumed, which favours maintenance of healthy body weight (United States Department of Agriculture, 2009). In terms of nutrient composition, fruits and vegetables are a major source of macronutrients such as fibre and micronutrients such as minerals and vitamins C (thiamine), riboflavin, B-6, niacin, foliate, and vitamins A, and E. Phytochemicals in fruits and vegetables, such as polyphenolics, carotenoids, and glucosinolates, may also have nutritional value (Barrett, 2007). According to Rekhy & McConchie, (2014), eating a range of coloured fruits and vegetables provides antioxidants, which work together to protect our bodies. ...
There is growing body of evidence highlighting the protective effect of fruits and vegetables but their intakes are still inadequate both in developed and developing countries. In Ghana, fruits and vegetables form part of every ones diet. However, several researches that have been conducted in the country indicate that people in the country are not eating enough fruits and vegetables especially the recommended five servings per day. This study therefore assesses the consumption pattern of fruits and vegetables in the Mampong Municipality. The study employed descriptive statistics and multiple linear regression to analyze the factors that influence consumption of fruits and vegetables, the knowledge level on fruits and vegetables, inclusion level of fruits and vegetables and whether the respondents were concern with the level of intake of fruits. Data used was from field survey of 140 respondents sampled from the municipality. The results indicated that most of the respondents in the municipality were able to take 1 – 3 servings of fruits and vegetables a day. Most of the respondents were however not aware of the WHO recommended minimum daily intake of 5 servings of fruits and vegetables. The regression model indicated that employment and education are significant to fruits and vegetables consumption. It is recommended that fruits and vegetables education be intensified in the country through the media or nutrition personnel. Also people should be made aware of the recommended minimum intake so that they can increase their intake in order to meet the recommended daily intake.
... These deterioration and losses decrease the quality of the vegetables.Vitamin C which a major micronutrient in vegetables begins to degrade immediately after harvest [3]. Loss of vitamin C is often used as an indicator of quality deterioration during postharvest handling including transportation, storage, and processing because it is highly susceptible to chemical and enzymatic oxidation and is highly water soluble [4]. Quantitative and qualitative losses of leafy vegetables mainly occur after harvesting, during transportation, processing and in storage [5]. ...
Vegetables are highly perishable commodities that easily get spoilt or deteriorate during handling along the supply chain from the producer to the final consumer. This study aims to compare the microbiological efficacy of hessian bags and non hessian bags on leafy vegetables (Telfairia occidentalis) Ugu and (Ocimum gratissimum) Nchuanwu leaves using hessian bags and non-hessian bagsduring distribution. Standard procedures on microbial count, isolationof microorganisms, purification of microbial isolates, biochemical identification of isolateswasused to identify the microorganisms present. The microbial load of the leafy vegetables from farmland to consumer increased progressively along the distribution chain. Staphylococcus species were the predominant bacteria in the leafy vegetables from the farmland. Other bacteria found were Pseudomonas, Bacillus spp, Staphylococcus spp, Escherichia coli and fungi Penicillium spp, Aspergillus niger, Rhodotorula spp, Fusarium spp, Mucor spp. The study showed that the microbial contents of the vegetables increased across the distribution line from farmland to consumer irrespective of the use of hessian bags.
... A B C Barrett, 2016Anon, 2004, and Florkowski et al., 2009Anon, 2007and Anon, 2013Anon, 2007Anon, 2016 ...
To maintain good health and obtain energy all living organisms need feeding. A complete food for humans is the one which contain protein, carbohydrates, fats, vitamins, minerals, and fiber. Protein, carbohydrates, and fats are major sources of energy while vitamins and minerals though they are needed in less amounts have vital role in human health and nutrition. Fruits and vegetables are major sources of food such carbohydrates, proteins, vitamins, mineral and fiber. Taking fruits and vegetables as food helps in neutralization of free radicles which are produced in human body through food taken from animal sources. Many animal-based foods such as meat, milk, eggs etc. produces chemical compounds which are not broken down by enzymes and acids produced in human digestive system. Antioxidant compounds which are present in fruits and vegetables react with these free radicles and neutralize its effects. Minerals are compounds which are originated from soil and living organisms are not able to produce it. Minerals have vital role in health of human, animals and even plant. Plants absorb nutrients from soils and human and animal would need to use plants as food to obtain required amount of minerals. Some minerals are supplied to living organism through water consumption.
برای داشتن صحت کامل و دریافت انرژی مورد نیاز همه اجسام حیه به تغذیه ضرورت دارند. یک غذای کامل برای انسانها غذای است که دارای پروتین، کاربوهایدریت، شحم، ویتامین ها، منرال ها و فایبر باشد. پروتین، کاربوهایدریت و شحم منابع عمده انرژي بوده و ویتامین و منرال ها اگر چه به اندازه نسبتاٌ کم نیاز است ولی در صحت و سلامتی انسانها سهم بارز را دارا میباشد. میوه جات و سبزیجات منابع مهم مواد غذایی انسانها از جمله کاربوهایدریت، پروتین، ویتامین، منرال ها و فایبر هستند. مصرف میوه جات و سبزیجات در خنثی کردن رادیکل های آزاد (Free Radical) که از خوردن محصولات حیوانی در بدن تولید میشود، کمک میکند. در غذا های حیوانی مانند گوشت، شیر، تخم مرغ وغیره عناصر بیشتر به صورت ترکیباتی وجود دارند که توسط تیزاب ها ترشح شده در بدن قابل تجزیه نیستند. مواد جلوگیری کننده تحمض (Antioxidant) که در میوه جات و سبزیجات وجود دارد رادیکل های آزاد را با خود ترکیب نموده، از بدن خارج میسازد و اثرات آنها را خنثی میکنند. منرال ها عناصر هستند که از خاک منشأ گرفته و توسط اجسام حیه تولید شده نمی تواند. منرال ها برای سالم بودن انسان ها، حیوانات و نباتات ضروری می باشد. نباتات منرال ها را از خاک جذب می نماید و حیوانات و انسان ها منرال های مورد ضرورت خویش را از خوردن سبزیجات، میوه جات و دیگر نباتات بدست می آورد. بعضی منرال ها از نوشیدن آب نیز به بدن انسان تهیه می گردد. در این مقاله معلومات مختصر راجع به اهمیت غذایی میوه جات و سبزیجات به خصوص رول منرال ها در بدن انسان ارائه شده است.
... Mechanism of mineral uptake by plants, though similar, differ in individual's uptake rate. In addition, cultivar type, soil type, production system and weather conditions (temperature, humidity, daylight hours, etc.) during growth have been reported to also affect the level of mineral contents in plants (Barrett, 2007). ...
Nutritional loss during food processing has become a major concern in recent times especially major essential mineral nutrients. There is a need to know the appropriate cooking time for green leafy vegetables since they provide essential minerals in the diet of man. Hence, the cooking effect on commonly consumed green leafy vegetables in Lagos State was undertaken to ascertain the level of mineral reduction with cooking time. Green leafy vegetables were collected from Lagos Polytechnic farm and subjected to cooking for 5, 10, 15 and 30 min. Potassium, sodium, magnesium, calcium, phosphorus and iron contents were evaluated in the treated vegetables using an Atomic Absorption Spectrometer. The study showed Jute mallow to be rich in potassium (38.43±0.06 mg/g), sodium (173.44±0.01 mg/g) and phosphorus (174.64±0.00 mg/g); Waterleaf contained magnesium (38.43±0.06 mg/g) and calcium (74.88±0.02 mg/g), while bitter leaf was a good source of iron (18.85±0.01 mg/g). Both Lagos and African spinach had the lowest mineral contents when compared to the other vegetables. However, there was a significant reduction (p<0.05) in mineral contents with cooking duration, with waterleaf having the highest percentage mineral depletion (>40%) after 5 min of cooking. Moderate mineral reduction was observed in both bitter leaf and jute mallow. Fluted pumpkin, Lagos and African spinach showed a minimal mineral reduction in the study. Cooking for not more than 5 min for waterleaf, and for <15 min for both bitter leaf and jute mallow was considered best for retention of ~50% of the original mineral contents, while fluted pumpkin, and Lagos and African spinach still retained more than 50% of their initial mineral contents even after 30 min of cooking.
... Drying was completed within different days for different crops and only % moisture contents of the foods were evaluated. During solar drying, foods are exposed to solar radiation which in the presence of oxygen might result into loss of nutrients such as vitamins A and C (Kabasa et al., 2004) as well as changes in sensory quality that might not be desirable (Barrett, 2007). Drying of potatoes with NSPRI solar dryers may be a viable option to reduce postharvest loss and assist farmers to prepare a variety of potato-based food products. ...
In this study, drying technology was employed to process fresh orange fleshed sweet potatoes (OFSP) into dried slices using NSPRI improved solar tent dryer, parabolic shaped solar tent dryer in comparison with open air drying and its effect on the chemical, physico-chemical and mineral constituents of dried OFSP slices was investigated. Results showed that the dried-OFSP contained ash (3.69-4.09 %), fat (4.09-5.09 %), crude fibre (4.69-5.15 %), protein (5.87-8.28 %), carbohydrate (78.22-82.21 %), vitamin C (8.55-20.49 mg/100g), phenolics (0.1-1.28 mg/kg), flavonoids (984-145 mg/kg) and reducing sugar (35.01-82.23 g/100g). The total titratable acidity of the dried OFSP slices varied between 0.56-0.89 %, total soluble solids ranged between 5.70-7.00 °Brix while pH ranged between 4.94-6.47. Zinc, magnesium, potassium, calcium, sodium, iron were present in varying levels but aluminium, lead and cadmium were not detected in all the samples. This study therefore showed that good quality dried OFSP slices with appreciable nutrient content can be obtained from drying in NSPRI solar tent dryers especially with the use of the parabolic shaped solar tent dryer. Thus, the parabolic solar tent dryer is recommended for drying crops. Keywords: Drying technology, Orange fleshed sweet potato, NSPRI solar dyers, Physicochemical properties
... The fruits and vegetables are the rich sources of minerals essential for health (Barrett, 2007). Mineral content is not much affected by the drying (Kresic, 2004), while the organic and mineral constituents amount was found to increase during drying (Aliero and Abdullahi, 2009). ...
... Nutritional quality parameters of fresh produce change with storage time, and quantification is necessary to determine shelf life (Barrett et al., 2010;Idah et al., 2010). Most fruits and vegetables are composed of 70% to 90% water and once separated from their source of nutrients, they undergo higher rates of respiration, resulting in moisture loss, quality and nutrient degradation, and potential microbial spoilage (Barrett, 2007). ...
The fruits of Msasa and Jaffa orange varieties were harvested and subjected to post-harvest treatments namely; dipping in hexanal, dipping in calcium chloride and compared with untreated control; and they were stored at ambient (28 ± 2°C) and reduced temperatures (18 ± 2°C) conditions. Data were collected on the 0, 4th, 8th, and 12th days from the date of fruit harvest. Chemical analyses were conducted to determine vitamin C content, total sugars, reducing sugars and total flavonoids. Post-harvest treatments had a significant effect on vitamin C and total flavonoids of Jaffa orange fruit. Hexanal treated fruit had higher values of total flavonoids, vitamin C, and total sugars compared to calcium chloride treated and control fruit. The storage durations showed significant effects on the vitamin C content of Jaffa, total flavonoids, the total and reducing sugars of both fruit varieties. Vitamin C and total flavonoids decreased with increasing storage duration of fruit. The significant interactions of factors were observed on total sugar which was increasing with increasing storage duration, but higher in hexanal treated and ambient stored fruit. Based on consumer acceptance test, the hexanal treated fruits were the most liked followed by calcium chloride treated and untreated fruits based on the appearance, taste, texture and overall acceptability.
... Well-managed hydroponic operations can have several advantages. Water recirculation through the system can sometimes reduce water use by as much as 95% compared to field growing, and farmers can locate high-yielding hydroponic units near population centers in harsh climates to reduce transit time and nutrient loss during shipment (Barrett, 2007;Despommier, 2010;Touliatos, Dodd, & Mcainsh, 2016). In addition, since hydroponic systems typically avoid soil and reduce the need for pesticides, crops often stay cleaner at harvest (Brechner & Both, 1996;Despommier, 2010;Kaiser & Ernst, 2012). ...
Recent controversy about the inclusion of hydroponics in the United States Department of Agriculture (USDA) organic program has highlighted uncertainty about marketing hydroponic crops. In a controversial vote in November 2017, the National Organic Standards Board chose not to recommend that hydroponic farms be banned from organic certification. It is still unclear, however, how consumers perceive and value hydroponic production. This study used a non‐hypothetical choice experiment to estimate consumers’ willingness to pay for hydroponic and traditional lettuce both with and without organic certification. No hydroponic premium was found, but exposing consumers to different kinds of information about hydroponics significantly affected consumers’ preference formation. Findings generally suggest that the National Organic Program should consider ways to ensure the stability of organic premiums as perceptions about hydroponics evolve. This article is protected by copyright. All rights reserved
... The nutrient density is typically an indicator of proportion of nutrients present in a food item and can be selected as a measure of the quality of food. The nutrient content composition changes in food items depend upon the particular nutrient, the commodity, post-harvest handling, storage and home cooking conditions [7]. The time between the harvest and the final consumption also significantly affects of food. ...
... In the meantime, as discussed in Sections 3.4.5 and 4.2, it is relevant to consider the nutritional values of the different processed products. The transformation of food qualities (nutrient content, such as, carbohydrate, fiber, vitamins, minerals, essential amino acids, energy, fat and protein) are differently-varied according to (i) the types of foods (fresh and processed F&V products) (Nutrient Data Lab, 2007); and (ii) storage and preparation processes (Barrett, 2007;Bouzari et al., 2015aBouzari et al., , 2015bRickman et al., 2007;Severi et al., 1997). For example, depending on the types of food commodity, freezing and canning processes may preserve the nutrient value, but the initial thermal treatment of a processed product can cause loss of vitamin C and the B vitamins. ...
This study discusses importance of assessing environmental sustainability of fruits and vegetable (F&V) production sector in future climate change (CC) scenarios. For the current production scenario, life cycle environmental footprints of F&V supply chain are discussed considering the influences of: agro-climates, production systems, raw material inputs, post-harvest managements to the products' yield and quality. Potential risks of CC to the sector are discussed in the context of elevated global temperature and carbon dioxide level, ozone depletion and changes in precipitation patterns. Potential risks due to CC are on the productivity and the quality of F&V products, such as texture, color, maturity and nutrients. Increased risk of failure of the current crop protection strategies, e.g. due to pest infestations and different crop-water and nutrient stresses are among the short and long-term risks. It also discusses potential adaptation and mitigation measures to CC, and therefrom argues on the related environmental consequences in the supply chain. From the LCA studies, it was revealed that environmental impacts of F&V supply chain varied as per agro-ecological characteristics and farming systems, e.g. greenhouse vs open-field, organic vs conventional, and grown in different agro-climatic conditions. The nexus among the climatic stresses, potential adaptation and mitigation measures, hence were in the form of potential changes in the raw material inputs and resource flows depending on the preferred future agro-management strategies and farming practices. Adaptation and other management options, included are, changes in: crop calendar, nutrient and pest management strategies, post-harvest handling and improved preservation of F&V products. These are argued eventually being determining factors leading to different environmental footprints compared to the existing management scenarios. Prospective life cycle environmental evaluation of F&V supply chain considering the relationship among product yield and qualities, CC stresses and potential adaptation and mitigation measures is thus a new thrust and direction.
... Although nutrient content did not differ, such eggs could differ in attractiveness and suitability for parasitoids. The temperature of deployment (22.5 or 34.5°C) in our experiment did not impact nutrient content of previously frozen BMSB eggs, even though high temperatures are known to degrade nutritional value of fruits and vegetables (Barrett 2007). However, temperature does impact development of BMSB eggs and the parasitoids within them. ...
Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug (BMSB), has become a major pest. Seven experiments examined the nutrient content of their eggs in the context of female reproductive investment and use for experiments. Among 542 clusters examined, an average egg contained 23.50 ± 0.561 µg lipid, 3.17 ± 0.089 µg glycogen, and 3.08 ± 0.056 µg sugar. Mature eggs within a female’s ovary can make up 61% of her total lipid, 35% of glycogen, and 20% of sugar levels. Eggs obtained from a colony reared on a steady diet are expected to have consistent nutrient content. The age of a parental female only slightly affected the lipid level of oviposited eggs but did not affect glycogen or sugar levels. However, egg nutrient content can differ substantially by the source of the parental females; wild eggs had higher lipid but lower sugar content than colony-produced eggs. Further, the length of time that eggs are frozen influenced egg nutrient content. Freshly laid eggs had higher lipid and lower sugar levels than eggs frozen for 1 or 2 yr. Whether an egg turned grey following removal from cold storage did not affect nutrient content, nor did being frozen within 1 or 3 d of oviposition. The temperature at which eggs were left exposed did not impact egg nutrient content, but glycogen decreased and sugar increased with deployment time. This information combined with how factors affect host selection by natural enemies will help refine future experiments that use BMSB egg clusters.
... Shelf life affects food quality, which in turn influences the consumer's buying decisions. [4] Shelf life determination: can be done either with or without specialized equipment. There are two methods of shelf life determination. ...
Pre-harvest quality of Cauliflower depends upon growing climate and
is also affected by the particular cultivar (PUSA Katki, Giant Snow
Ball, Himani etc.), soil type, production system (Conventional,
Organic).But post-harvest treatment largely determines final quality,
whether a crop is sold for fresh consumption, or used as an ingredient
in a processed food. Each crop has an optimum range for storage
temperature and humidity on which its shelf life depends. To develop
the shelf life equations of Cauliflower various intrinsic and extrinsic
vegetable parameters are studied. Relationship between these
parameters is used to develop generalized mathematical equation of
Shelf Life of Cauliflower in terms of important of Cold Storage
operating parameters namely Temperature and Relative Humidity. To
solve this generalized mathematical equation, Arrhenius reaction
kinematics approach is used to generate shelf life equations in terms of
three important quality parameters of Cauliflower namely Moisture
Loss, Energy Value and Vitamin C. Changes in these quality
parameters w.r.to variation in Temperature and Relative Humidity are
measured with standard procedures in laboratory . Then by fixing
kinematics reaction order and differential rate laws, shelf life equations
for Cauliflower are developed. Laboratory measured values are
compared with calculated values obtained from shelf life equations.
These equations are useful to retain the Cauliflower quality and its
nutritional value in post-harvest management. These equations will
definitely provide fundamental platform to design and develop cost
effective cold storages for Vegetable Preservation in India.
... Myrosinase is a relatively thermolabile enzyme. For instance, broccoli myrosinase is inactivated in the temperature range between 40 • C and 60 • C. In the human gut, glucosinolates can be hydrolyzed by microbial myrosinase (Barret, 2007;Van Eylen et al., 2007). However, this appears to be insufficient since several studies in humans have found that inactivation of myrosinase in cruciferous vegetables prior to ingestion substantially decreases the bioavailability of isothiocyanates (Shapiro et al., 2001). ...
Abstract Pulsed electric field (PEF) processing is an effective food preservation technique for the pasteurization of pumpable food products since it inactivates vegetative microbial cells at ambient to moderate temperature without significantly affecting the nutritional and sensorial quality of the product. However, conflicting views are expressed about the effect of PEF on enzymes. In this review, which is part 2 of a series of reviews dealing with the effectiveness of novel food preservation technologies for controlling enzymes, the scientific literature over the last decade on the effect of PEF on plant enzymes in particular is critically reviewed to shed more light on the issue. The existing evidence indicates that PEF can cause substantial inactivation of most enzymes, although a much more intense process is required compared to microbial inactivation. Depending on the processing condition and the origin of the enzyme, up to 97% inactivation of pectin methylesterase, polyphenol oxidase and peroxidase as well as no inactivation have been reported following PEF treatment. Both electro-chemical effects and Ohmic heating appear to contribute to the observed inactivation, although the relative contribution depends on a number of factors including the design of the PEF chamber, the processing condition and the composition of the medium.
... Myrosinase is a relatively thermolabile enzyme. For instance, broccoli myrosinase is inactivated in the temperature range between 40 • C and 60 • C. In the human gut, glucosinolates can be hydrolyzed by microbial myrosinase (Barret, 2007;Van Eylen et al., 2007). However, this appears to be insufficient since several studies in humans have found that inactivation of myrosinase in cruciferous vegetables prior to ingestion substantially decreases the bioavailability of isothiocyanates (Shapiro et al., 2001). ...
The activity of endogenous deteriorative enzymes together with microbial growth (with associated enzymatic activity) and/or other non-enzymatic (usually oxidative) reactions considerably shorten the shelf life of fruits and vegetable products. Thermal processing is commonly used by the food industry for enzyme and microbial inactivation and is generally effective in this regard. However, thermal processing may cause undesirable changes in product's sensory as well as nutritional attributes. Over the last 20 years, there has been a great deal of interest shown by both the food industry and academia in exploring alternative food processing technologies that use minimal heat and/or preservatives. One of the technologies that have been investigated in this context is high-pressure processing (HPP). This review deals with HPP focusing on its effectiveness for controlling quality-degrading enzymes in horticultural products. The scientific literature on the effects of HPP on plant enzymes, mechanism of action, and intrinsic and extrinsic factors that influence the effectiveness of HPP for controlling plant enzymes is critically reviewed. HPP inactivates vegetative microbial cells at ambient temperature conditions, resulting in a very high retention of the nutritional and sensory characteristics of the fresh product. Enzymes such as polyphenol oxidase (PPO), peroxidase (POD), and pectin methylesterase (PME) are highly resistant to HPP and are at most partially inactivated under commercially feasible conditions, although their sensitivity towards pressure depends on their origin as well as their environment. Polygalacturonase (PG) and lipoxygenase (LOX) on the other hand are relatively more pressure sensitive and can be substantially inactivated by HPP at commercially feasible conditions. The retention and activation of enzymes such as PME by HPP can be beneficially used for improving the texture and other quality attributes of processed horticultural products as well as for creating novel structures that are not feasible with thermal processing.
... Loss of carotenoids to some extent and browning reactions during thermal processing could be responsible for the decrease in red color component. Barrett (2008) reported that the effects of processing on maximum nutritional values of fruits with regard to studies on nutrient concentration in fresh and canned fruits. ...
Mango (Magnifera indica L) is grown in the tropical and sub tropical regions of India. The fruit has a high commercial value depending on the color, flavor and pulp characteristics of the cultivar. Sindura, Mallika and Totapuri cultivars grown in southern Karnataka were investigated for the physical chemical characteristics and the effect of processing on the quality characteristics. Sindura, Mallika and Totapuri mango cultivars had significantly different physico chemical and compositional characteristics. Sindura cultivar had a characteristic red color in the peel with high carotenoid content and slightly lower pulp content. Mallika contained higher pulp content with a pale yellow color in the peel and higher total soluble solids. Totapuri contained slightly lower pulp content than Mallika, lower total soluble solids and lower carotenoids among the cultivars. Sindura and Mallika pulps had significantly higher viscosity than Totapuri. Processing of the pulps resulted in significant decrease of carotenoids irrespective of the cultivar. Sensory quality of canned mango slices showed higher acceptability for Mallika followed by Sindura and Totapuri. Mango nectar prepared from Sindura was highly acceptable followed by Totapuri and Mallika. Processing of these underutilized mango cultivars into puree, nectar, juice beverages and slices, can result in value addition and popularization.
Fruits and vegetables are living entities even after harvest with differential composition of nutrients with lot many biochemical and physiological process happening inside them. They are rich in water; and carbohydrate, protein, lipids, vitamins, minerals and bioactive compounds are their major components, which can be altered by the metabolic processes such as respiration, transpiration and ripening. Fruit development, maturity and ripening are genetically regulated phenomenon leading to consumer appreciable quality attributes. Fruit and vegetable vary in their chemistry and physiology, which decides their processing stability, palatable quality, shelf life and storage behavior. Proper understanding of fruit chemistry and physiology, and control of ripening process using better storage techniques and genetic modification will help in reducing undesirable changes occurring due to ripening, hence keeping the produce more aesthetically as well as nutritionally sound for longer duration.
Home vegetable gardening has numerous documented benefits, including savings on the family food bill. How can a gardener calculate cost savings from a garden? Which vegetables cost more to grow in the garden and which cost less? This 10-page fact sheet written by Kevin Athearn, Hannah Wooten, Liz Felter, Catherine G. Campbell, Jessica M. Ryals, Matthew C. Lollar, Juanita Popenoe, Lorna Bravo, LuAnn Duncan, Christa Court, and Wendy Wilber and published by the UF/IFAS Food and Resource Economics Department helps home gardeners estimate the costs and cost savings from vegetable gardening
The consumer demand for locally grown fresh produce is continuously increasing in the United States. The high tunnel systems have been successfully utilized by small acreage growers for local production. Consumers are typically assessing appearance, freshness, flavor and aroma when purchasing produce. A common perception is that locally grown produce tastes better than nonlocal. However, there is not much evidence for supporting this claim. The objective of this study was to identify consumer acceptability and the sensory characteristics/differences of locally grown spinach in open field or in high tunnel and nonlocal commercially grown spinach. Spinach, Spinacia oleracea cv. “Corvair” was grown in open field and in high tunnel at Kansas State Univ. Olathe Horticulture Research and Extension Center (OHREC) in spring 2017 and the commercially grown spinach was purchased at a local retail store. A consumer study (n = 205) was conducted at Kansas State Univ., Olathe campus, and a descriptive sensory analysis was conducted by a highly trained descriptive analysis panel in the Center for Sensory Analysis and Consumer Behavior at Kansas State Univ., Manhattan campus, in spring 2017. The consumer test showed that high tunnel spinach scored significantly higher in overall liking (P < 0.0001), flavor liking (P < 0.0001), and texture liking (P < 0.05) when compared to open field and store purchased spinach. Descriptive analysis showed that locally grown spinach had higher intensity of attributes that indicate premium quality, such as green color and green/spinach flavors. Our results indicate that locally grown spinach was preferred from the consumers for its high organoleptic quality. Locally grown spinach demonstrated high intensity in a set of sensory attributes that suggest a product with premium organoleptic quality. Correspondingly to these results, consumers liked spinach produced locally in high tunnels the most. The results of this study can be used for developing marketing strategies that are aiming specifically to the consumer niche that is seeking fresh produce of high organoleptic quality.
Fruits are rich in phytochemicals that protect human populations against diseases. Sweet orange is a good source of potassium, folate, and vitamin C. It also contains phenolic compounds that are important antioxidants. Tanzania is a major sweet orange producer in East Africa. Application of hexanal to reduce preharvest and postharvest losses was tested in Tanga and Morogoro regions in Tanzania. The effectiveness of hexanal in reducing preharvest and postharvest losses of oranges was previously unknown. Hexanal treatment significantly reduced the incidence of pest damage of orange varieties compared with untreated control. Postharvest dip treatment of hexanal at 0.02 percent significantly maintained fruit freshness and firmness of the tested orange varieties. Fruit freshness, firmness and absence of pest defects on fruits are the most important market attributes that guide consumers when buying fresh oranges.
The effect of commercial canning and freezing on the nutritional content of fresh apricots was investigated. Processed samples were analyzed post‐processing and after 3 months of storage and compared directly to fresh apricots from the same source. Vitamin C, beta‐carotene, total phenols, and antioxidants were quantified. Compared to fresh, canned apricots initially exhibited similar levels of antioxidants, a 17% increase in beta‐carotene, and a 48% increase in phenols, while vitamin C was reduced by 37%. After 3 months of storage, antioxidant levels were 47% higher than fresh. Vitamin C did not change significantly following storage and beta‐carotene decreased by 15%. The canned apricot fruit packed in light syrup did not have higher total soluble solids (TSS) levels indicating no increase in fruit sugar content. Frozen apricots exhibited large increases in antioxidants (529%), beta‐carotene (35%), vitamin C (3,370%), and phenols (406%) compared to fresh. After 3 months of storage, frozen apricots decreased in vitamin C (29%) and phenols (17%), but remained 2,375% and 318% higher than fresh, respectively. Beta‐carotene increased during storage, reaching levels 56% higher than fresh while antioxidant activity was unchanged. This study demonstrates that key nutrients in canned and frozen apricots are retained or amplified upon processing, with the exception of vitamin C in canned apricots. The routine addition of citric and ascorbic acid to fruit prior to freezing resulted in significantly higher antioxidants, vitamin C, and phenols. Consumers eating canned or frozen apricots can feel confident of similar or superior nutritional content as compared to fresh apricots.
Practical Application
The apricot industry is limited by the short shelf life of the fruit and consumer belief that processed produce is not as nutritious as fresh. Assessing the nutritional content of canned and frozen apricots and determining that processed apricots can deliver nearly comparable nutrient levels to fresh apricots provides the evidence needed to dispel these misconceptions and potentially increase demand for processed apricots among consumers.
Super food is an informal term for foods that benefit the body in many different ways. Super foods help to meet several dietary needs and are great sources of essential vitamin and minerals also fight disease and sickness, making them powerful anti-aging tools. Some super like avocado, rambuten, dragon fruits blackberries, blueberries, corn, garlic, ginger, onion berries, etc. All foods that have been associated with preventing age are called antiaging foods. The aging process is natural of life for every person. There are many products and methods to prevent and reduce aging, from antiaging skin care The study was carried out to determine the different types of super food product and shilf life (packaging) of orange squash and ginger ele juice, kiwi sherbet produced were prepared and were processed into juices and sensory analysis of the juices were done. Fruits juices of orange, which was stored for 6o day in orange squash, and ginger ele, product were pressurization and storage in packaging glass bottles (250ml). Sensory evaluation showed that there was no significant difference among the juices from four samples considering color and overall acceptability. But considering flavor and texture there was significant difference among the juices from three samples and sample 3 was the best. However, the shelf life of juice was established within 30 days.
As the world population grows and becomes more educated as to the link between food and health, nutritional research is shifting from alleviating nutrient deficiencies to chronic disease prevention, altering the focus from food availability to healthy food choices for increased longevity and quality of life. In both developing and developed countries, as this awareness becomes acute so does the direct influence on marketing to the consumer by the manufacturer. The consumer and the food manufacturer become partners in the responsibility to assure a safe food supply. Through health education and awareness on the part of the consumer and adequate availability, affordability, and regulatory compliance on the part of the manufacturer, optimum supply and safety in the food industry are realistically achieved to the greatest benefit of all stakeholders. Influences such as demographic/culture, peers, food environments and attitudes, and economic and government policies are among the many factors that must be considered in the process of promoting wellness through healthy diets. Marketing both reflects this and, at its best, works to support wholesome choices.
Minerals, total phenolics, and fiber were analyzed in several fruit and vegetable commodities to evaluate the differences between fresh and frozen produce. Magnesium, calcium, iron, zinc, and copper were evaluated in corn, carrots, broccoli, spinach, peas, green beans, strawberries, and blueberries. Each commodity was harvested fresh and split into two batches. Half of each commodity was kept fresh and the other half was frozen, and the nutrient content was analyzed over three storage times per treatment. The retention of nutrients was highly dependent on the commodity, but the majority of the commodities showed no significant difference between fresh and frozen for all analytes (p < 0.05).
Four vitamins were analyzed in several fruit and vegetable commodities to evaluate the differences between fresh and frozen produce. Ascorbic acid, riboflavin, α-tocopherol, and β-carotene were evaluated in corn, carrots, broccoli, spinach, peas, green beans, strawberries, and blueberries. Samples of each commodity were harvested, processed, and analyzed for nutrient content at three storage times per treatment. Ascorbic acid showed no significant difference for 5 of the 8 commodities and was higher in frozen samples than fresh for the remaining 3 commodities. Apart from broccoli and peas, which were higher and lower in frozen vs. fresh samples, respectively, none of the commodities showed significant differences with respect to riboflavin content. Three commodities had higher levels of α-tocopherol in the frozen samples, while the remaining commodities showed no significant difference between fresh and frozen. β-carotene was not found in significant amounts in blueberries, strawberries, and corn. Peas, carrots, and spinach were lower in β-carotene in the frozen samples, while green beans and spinach showed no significant difference between the two preservation methods. Overall, the vitamin content of the frozen commodities was comparable and occasionally higher than their fresh counterparts. Beta carotene, however, was found to decrease drastically in some commodities.
Despite the recommendations of international health organizations and scientific research carried out around the world, consumers do not take in sufficient quantities of healthy fruit and vegetable products. The use of new, 'advanced' preservation methods creates a unique opportunity for food manufacturers to retain nutrient content similar to that found in fresh fruits and vegetables. This review presents a summary of the published literature regarding the potential of high-pressure and microwave preservation, the most studied of the 'advanced' processes, to retain the natural vitamin A, B, C, phenolic, mineral and fiber content in fruits and vegetables at the time of harvest. Comparisons are made with more traditional preservation methods that utilize thermal processing. Case studies on specific commodities which have received the most attention are highlighted; these include apples, carrots, oranges, tomatoes and spinach. In addition to summarizing the literature, the review includes a discussion of postharvest losses in general and factors affecting nutrient losses in fruits and vegetables. Recommendations are made for future research required to evaluate these advanced process methods.
We evaluated the ability of fresh tomatoes and processed tomato products (whole, diced, sauce, puree, and juice) to inhibit in vitro the formation of N-Nitrosomorpholine (NMOR), under conditions similar to the human stomach. The amount of NMOR that was formed averaged 23% to 82% that of the controls, on an equal wet weight basis, with paste being the most inhibitory. On an equal soluble solids basis, the amount of NMOR formed in the presence of products averaged 82% to 88% of that formed in the distilled water control. Fresh tomatoes showed greatest inhibition of nitrosation (NMOR formation averaged 80% of control), and processed tomatoes showed similar inhibition (NMOR 82% to 88% of the control). Ascorbic acid content was the strongest predictor of ability to inhibit NMOR formation. Processed tomato products inhibited nitrosation to a similar extent as had been reported for fresh tomatoes.
Regular consumption of dietary antioxidants may reduce the risk of several serious diseases. As vegetables are a major source of antioxidants it is desirable to assess their antioxidant activity and compare different processing and preparation methods. The total antioxidant activity was determined in water- and lipid-soluble extracts from fresh, stored and frozen vegetables. The contribution of individual compounds to total antioxidant activity was estimated. In stored vegetables at ambient or chill temperatures antioxidant activity declined. Blanching and freezing of peas and spinach reduced water-soluble antioxidant activity by 30 and 50%, respectively, thereafter levels remained constant on storage at −20 °C. Samples of frozen peas and spinach purchased from retail outlets had substantially higher antioxidant activity than canned or jarred samples. In a comparison of cooking methods, microwave and boiling for short periods had a negligible effect on total antioxidant activity, but substantial losses occurred after prolonged boiling in water.