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Are folates, carotenoids and vitamin C affected by cooking? Four domestic procedures are compared on a large diversity of frozen vegetables
... Delchier et al. (2013) also observed a 20% folate loss due to leaching in green beans during the canning process. This result was confirmed by Bureau et al. (2015), who assessed the effect of domestic cooking of frozen vegetables on folate losses. These authors also found indications of losses caused by water-soluble vitamins diffusion in all procedures tested. ...
... Thermal treatment is required for the reliable elimination of endogenous enzymes (in a preliminary experiment some browning was observed in non-steamed material at 25 • C) and of cell membranes so that the vitamins could diffuse freely. Steaming appeared to be the most efficient process to defrost the plant material for our study due to its low impact on the degradation of the vitamins, about 10% for vitamin C and no significant loss for folate (Bureau et al., 2015). ...
... Half-lives were determined for vitamin C at 85 • C and were 79 min in peas and 516 min in Brussels sprouts. Bureau et al. (2015) found that 66%, 71% and 9% of vitamin C was retained in water-cooked peas, Brussels sprouts, or spinach, respectively, while 100%, 93% and 74% were retained in steamed peas, Brussels sprouts, or spinach after 10 min of cooking. For comparison, Al Fata (2017) reported a half-life of ascorbic acid of 80 min in air and >320 min under strict anaerobic conditions in model solutions at 95 • C and pH 3.5. ...
... In this way, food technology has been improved to ensure that food processing results in quality and quantity products for the population. However, although nutritional losses during processing are often unavoidable, they can be minimized by the use of appropriate processing technologies 13,14 . ...
... Vitamins are sensitive compounds that can be degraded by different factors, such as temperature, oxygen, light, humidity, pH, duration of treatment, etc. 14,11 . Although there are studies that correlate industrial processing and nutritional quality, knowledge of this subject is dispersed and insufficient due to the complexity of each micronutrient and its interaction with the food matrix. ...
... The interaction between constituents present in foods is also a relevant issue and dependent on the nutrient of interest. While folic acid exhibits lower thermal stability; cooking and digestive enzymes weaken the cell walls, disrupting the protein-carotenoid complexes, promoting the release and increased bioavailability of carotenoids 11,14,62 . In contrast, depending on the conditions, heat treatement can reduce carotenoids bioaccessibility, inducing structural changes in carotenoids, mainly isomerization, altering their solubility and consequently their micellarization 62 . ...
The supply of food products that present adequate nutritional quality is extremely important for maintaining the health of the population. Thus, different techniques have been used to obtain biofortified foods, with the aim of combating malnutrition caused by the absence of essential micronutrients, especially in the poorest populations. This review presents an overview of biofortification, with an emphasis on orange-flesh sweet potatoes (OFSP), and points out the effects of food processing on nutritional compounds. The identification of cultivars and biofortification actions to obtain biofortified OFSP by conventional breeding are presented as affordable strategies to supply β-carotene to alleviate vitamin A deficiency, without having ethical dilemmas related to transgenics. Studies using OFSP have shown promising results in obtaining foods with high levels of carotenoids. However, biofortified species must be validated for crop production viability, target micronutrient bioavailability and bioaccessibility, as well as the effect of processing on nutrients, so that the benefits to human health are effectively achieved.
... Moreover, the changes in the natural barriers in which some nutrients can be involved may result in the release from the matrix of bioactive components or, for those more polar, their loss in cooking water [11]. Different papers have studied the effect of different domestic cooking procedures on several phytochemicals (polyphenols, carotenoids, tocopherols, glucosinolates) and micronutrients (vitamins and minerals) on vegetables, with somehow contradictory results [11][12][13][14][15][16]. ...
... Being lipid soluble, carotenoids and tocols are not significantly lost into water-soluble mediums during processing. However, their content in vegetables can be significantly affected by domestic cooking processes in different ways [11][12][13][14][15]. The interactions between the two factors, vegetables and cooking procedures, were significant [12]. ...
... However, their content in vegetables can be significantly affected by domestic cooking processes in different ways [11][12][13][14][15]. The interactions between the two factors, vegetables and cooking procedures, were significant [12]. In some cases, a reduction was observed for their thermal lability and their sensitivity to oxidation. ...
Lipophilic antioxidants are essential components, which have been pointed as bioactive beneficial for human health. This study aimed at evaluating the effect of domestic cooking (boiling, steaming) on the main carotenoids (lutein and β-carotene) and tocols in four different green leafy vegetables: Sonchus asper L. Hill, Sonchus oleraceus L., Spinacia oleracea L. and Cichorium intybus L. The total content of the analyzed compounds was determined following the method of alkaline hydrolysis of the matrix and solvent extraction. The leaching of soluble solids after domestic cooking was found to determine a gain in the investigated bioactive compounds in the cooked vegetables, so to cause an apparent content increase in all leafy vegetables, when expressed as mg/100 g dry matter. Considering solid losses, all lipophilic compounds were not affected by boiling; on the contrary, steaming slightly significantly decreased the contents of lutein and β-carotene (on average 20 and 15%, respectively).
... With the exception of a few vegetables used in salads, virtually all traditional green leafy vegetables in Ghana are cooked to increase palatability, reduce bitterness and remove itchiness. However, their nutrient concentrations are affected during cooking [7][8][9]. This study, therefore, aimed at estimating the micronutrient contents of traditional green leafy vegetables from Ghana and their potential contribution to dietary recommended intakes. ...
... Carotenoids were extracted from the powders using the micro extraction technique described by Bureau et al. [9]. ...
... Spinach had the least vitamin C loss (44%) when boiled under the same conditions. Similar huge losses of vitamin C by blanching boiling or cooking in water have been reported in the literature [9,22,25,30]. As expected, the general trend was that samples with higher vitamin C in the raw vegetables retained higher vitamin C levels when boiled while Lunea taraxacifolia nearly lost all of its vitamin C content. ...
Micronutrient deficiency is a public health problem even though vegetable consumption could avert it. Vitamin C [Ascorbic acid (AA) and dehydroascorbate (DHAA)], β-carotene, lutein and vitamin B9 contents in seven traditional green leafy vegetables (raw and cooked) from Ghana were determined, to identify good sources and their potential contribution to Dietary Recommended Intakes. The micronutrients were quantified using spectrofluorimetric and HPLC/DAD analytical systems. Vitamin C content of samples ranged between 7.2 and 161 mg/100 g fresh weight. β-carotene content was within the ranges of 2.97 to 10.35 mg/100 g, Lutein 13.5 to 31.6 mg/100 g and total folate 18 to 146 μg /100 g. Lutein and β-carotene were in variable relative proportions (L/C from 1.6 to 6); Solanum macrocarpon and Amaranthus hybridus samples were particularly rich in lutein and β-carotene, respectively. Losses between 45 and 94% were observed for vitamin C, between 15 to 81% for β-carotene with the exception of an increase in Solanum macrocarpon and 17 to 80% for lutein under boiling. Similar drastic losses were recorded in microwaved samples; however, losses in lutein and folate were comparatively lower. The traditional green leafy vegetables studied were found to be very rich in the studied micronutrients, but cooking led to considerable losses. However, the cooked vegetables represent non-negligible sources of folate, good source of lutein and could provide up to 97% and 90% vitamin A and C Recommended Dietary Intakes respectively, when a 100 g is consumed. Improved cooking methods over the traditional methods of preparation are essential for retaining more micronutrients, for the benefit of consumers.
... With the exception of a few vegetables used in salads, virtually all traditional green leafy vegetables in Ghana are cooked to increase palatability, reduce bitterness and remove itchiness. However, their nutrient concentrations are affected during cooking [7][8][9]. This study, therefore, aimed at estimating the micronutrient contents of traditional green leafy vegetables from Ghana and their potential contribution to dietary recommended intakes. ...
... Carotenoids were extracted from the powders using the micro extraction technique described by Bureau et al. [9]. ...
... Spinach had the least vitamin C loss (44%) when boiled under the same conditions. Similar huge losses of vitamin C by blanching boiling or cooking in water have been reported in the literature [9,22,25,30]. As expected, the general trend was that samples with higher vitamin C in the raw vegetables retained higher vitamin C levels when boiled while Lunea taraxacifolia nearly lost all of its vitamin C content. ...
Micronutrient deficiency is a public health problem even though vegetable consumption could avert it. Vitamin C [Ascorbic acid (AA) and dehydroascorbate (DHAA)], β-carotene, lutein and vitamin B9 contents in seven traditional green leafy vegetables (raw and cooked) from Ghana were determined, to identify good sources and their potential contribution to Dietary Recommended Intakes. The micronutrients were quantified using spectrofluorimetric and HPLC/DAD analytical systems. Vitamin C content of samples ranged between 7.2 and 161 mg/100 g fresh weight. β-carotene content was within the ranges of 2.97 to 10.35 mg/100 g, Lutein 13.5 to 31.6 mg/100 g and total folate 18 to 146 µg /100 g. Lutein and β-carotene were in variable relative proportions (L/C from 1.6 to 6); Solanum macrocarpon and Amaranthus hybridus samples were particularly rich in lutein and β-carotene, respectively. Losses between 45 and 94% were observed for vitamin C, between 15 to 81% for β-carotene with the exception of an increase in Solanum macrocarpon and 17 to 80% for lutein under boiling. Similar drastic losses were recorded in microwaved samples; however, losses in lutein and folate were comparatively lower. The traditional green leafy vegetables studied were found to be very rich in the studied micronutrients, but cooking led to considerable losses. However, the cooked vegetables represent non-negligible sources of folate, good source of lutein and could provide up to 97% and 90% vitamin A and C Recommended Dietary Intakes respectively, when a 100 g is consumed. Improved cooking methods over the traditional methods of preparation are essential for retaining more micronutrients, for the benefit of consumers.
... Carotenoids were extracted on the nitrogen-ground powders, using the micro method described by Bureau et al. 16 They were quantified by HPLC-DAD (SPD-M20A Shimadzu Inc., Kyoto, Japan) using a C30 column (250 × 4.6 mm, particle size 3 μm; YMC Co, Kyoto, Japan) eluted at 30°C, flow rate 1.4 ml min −1 , with a methanol-methyl tert-butyl ether (MTBE) gradients. Lutein and β-carotene were quantified at 450 nm and lycopene (used as internal standard) at 503 nm. ...
... Lutein has been reported as the main carotenoid in the green vegetables. 16 Given the high lutein content of most of the TGLVs, promoting their consumption could enhance lutein intake of consumers. This may be important where eye disease concerns exist, 23 such as age-related macular diseases (AMDs) that have been related to lutein consumption, 24 evidence of which is beyond the scope of the present study. ...
... Boiling in water resulted in huge losses of vitamin C from 18.6% in Basella alba (Green stem) to 100% in Crassocephalum crepidioides. Blanching and cooking in water, similar to the domestic method, result in huge losses of vitamin C, 16,28 in agreement with our observations, given that vitamin C is a water-soluble vitamin that is easily affected by heat processing. 16 However, losses may be minimised if vegetables are boiled in smaller quantities of water 29 or steamed. ...
... Carotenoids were extracted on the nitrogen-ground powders, using the micro method described by Bureau et al. 16 They were quantified by HPLC-DAD (SPD-M20A Shimadzu Inc., Kyoto, Japan) using a C30 column (250 × 4.6 mm, particle size 3 μm; YMC Co, Kyoto, Japan) eluted at 30°C, flow rate 1.4 ml min −1 , with a methanol-methyl tert-butyl ether (MTBE) gradients. Lutein and β-carotene were quantified at 450 nm and lycopene (used as internal standard) at 503 nm. ...
... Lutein has been reported as the main carotenoid in the green vegetables. 16 Given the high lutein content of most of the TGLVs, promoting their consumption could enhance lutein intake of consumers. This may be important where eye disease concerns exist, 23 such as age-related macular diseases (AMDs) that have been related to lutein consumption, 24 evidence of which is beyond the scope of the present study. ...
... Boiling in water resulted in huge losses of vitamin C from 18.6% in Basella alba (Green stem) to 100% in Crassocephalum crepidioides. Blanching and cooking in water, similar to the domestic method, result in huge losses of vitamin C, 16,28 in agreement with our observations, given that vitamin C is a water-soluble vitamin that is easily affected by heat processing. 16 However, losses may be minimised if vegetables are boiled in smaller quantities of water 29 or steamed. ...
Objective: To determine the micronutrient composition of fresh and boiled traditional green leafy vegetables (TGLVs).
Design: Sixteen TGLVs categorised into cultivated and uncultivated vegetables were analysed for vitamin C (ascorbic acid [AA] and dehydroascorbate [DHAA]), β-carotene, lutein and minerals.
Results: Basella alba had the highest AA (72 mg/100 g) content; Vernonia amygdalina (unwashed), had the highest β-carotene and lutein concentrations (14.1 and 29.0 mg/100 g, respectively); Amaranthus hybridus had the highest AA (43 mg/100 g) and β-carotene (9.3 mg/100 g) content, for cultivated sp. Celosia argentea had the highest Fe content; Zn content of all the vegetables was low, 0.4–2.6 mg/100 g. Cooking resulted in significant losses in AA content in all the samples, 19% in B. alba to 100% in Crassocephalum crepidioides. Carotenoid losses were observed in 10 samples and six samples had increased values of β-carotene (12% to 183%) and lutein (64% to double).
Conclusion: Traditional green leafy vegetables studied were found to be rich in the micronutrients of interest, especially in carotenoids. Boiling of leafy vegetables, as traditionally done, led to considerable losses of the micronutrients. The micronutrient content of uncultivated leafy vegetables compared well with commonly cultivated species.
... The loss of epoxycarotenoids caused a corresponding slight significant decrease in total carotenoids, after steaming, in all vegetables (Table 2). From the literature, the effect of different food treatments on carotenoids is difficult to evaluate, due to the various process parameters that could affect their levels, such as temperature, heating time, oxygen, light, pH, and the type of food matrix [14][15][16][17]19], but, also, due to the different analytical procedures carried out for their determination [23]. ...
... The loss of epoxycarotenoids caused a corresponding slight significant decrease in total carotenoids, after steaming, in all vegetables ( Table 2). From the literature, the effect of different food treatments on carotenoids is difficult to evaluate, due to the various process parameters that could affect their levels, such as temperature, heating time, oxygen, light, pH, and the type of food matrix [14][15][16][17]19], but, also, due to the different analytical procedures carried out for their determination [23]. ...
Notwithstanding the increased interest in wild edible plants, little is known on how some domestic thermal processes can affect their content. The aim of this study was to investigate the amounts of minerals, B1 and B2 vitamins, tocols, and carotenoids in raw, boiled, and steamed wild edible plants, namely, Sonchus asper (L.) Hill s.l., Sonchus oleraceus L., Cichorium intybus L., and Beta vulgaris L. var cicla. All vegetables were confirmed as high sources of lutein (from 6 to 9 mg/100 g) and β-carotene (from 2 to 5 mg/100 g). Quite high amounts of violaxanthin and neoxanthin were found. Alfa-tocopherol and γ-tocopherol were the main tocols, with same contents in raw and processed vegetables (about 2.5 mg/100 g). The most abundant macro element and trace element were, respectively, potassium and iron. B1 and B2 vitamins were found in low amounts in almost all plants, with the exception of thiamine in Beta vulgaris (about 1.6 mg/100 g). Boiling led to a significant loss of minerals (up to 60%) and B-group vitamins (up to 100%), while, among carotenoids, it only affected violaxanthin levels (up to 90%). Steamed vegetables showed only a slight reduction, about 20%, in β-carotene and lutein, with a marked decrease in violaxanthin and neoxanthin. One hundred grams of all fresh and cooked plants can be claimed as a source of vitamin A and E.
... The difference in folate content of fresh and boiled samples were found to be statistically significant for all TGLVs (p<0.05). Studies have shown that folates are prone to losses by leaching when in direct contact with water (Bureau et al., 2015;Delchier et al., 2013Delchier et al., , 2012. Delchier et al. (2012) reported that when spinach and green beans were boiled in water, there was a > 50% loss of folate from the vegetables. ...
... Delchier et al. (2012) reported that when spinach and green beans were boiled in water, there was a > 50% loss of folate from the vegetables. Our findings are within the range for folate loss in boiled vegetables in previous literature (up to 94%) (Bureau et al., 2015, Delchier et al., 2012, Holasova et al., 2008. Given that most leafy vegetables are consumed in their cooked form in Nigeria, preparation methods of TGLVs that would allow for optimal retention of folate are necessary. ...
Folate is an important micronutrient in the prevention of neural tube defects and cardiovascular disease. Given its importance, it is necessary to establish accurately the folate content of food that could contribute significantly to dietary intake. The aim of the study was to quantify the folate content in raw and cooked traditional leafy and non‐leafy vegetables because there is a dearth of information on the folate content leafy vegetables found in Nigeria. The vegetables included: Corchorus olitorius, Adansonia digitata, Abelmoscus esculentus (fruit), Abelmoscus esculentus (leaves), Amaranthus hybridus, Launaea taraxacifolia, Solanum macrocarpon, and Crassocephalum crepidioides. They were further cooked in boiling water, until assessed as cooked according to Nigerian eating habits.
Folate is found in foods mainly as polyglutamate. The analysis of folate in the raw and cooked vegetable samples followed the process of extraction, deconjugation (using chicken pancreas deconjugase), derivatisation (a series of chemical reactions to convert all folate present in the deconjugated sample extracts, to 5‐methyltetrahydrofolic acid (THF‐5CH 3 ) monosodium glutamate and / or diglutamate), purification by affinity chromatography with Folate Binding Protein and quantification by HPLC equipped with fluorimetric detection.
Folate content in the raw samples ranged from 183.4 μg/100g (FW) in Corchorus olitorius to 21.5 μg/100g (FW) in Solanum macrocarpon leaves; and in the boiled samples from 48.6 μg/100g (FW) in Launaea taraxacifolia to 8.5 μg/100g (FW) in Solanum macrocarpon . Loss of folate in the boiled vegetables varied from 46.6% in Launaea taraxacifolia to 88.4% in Adansonia digitata .
Traditional green leafy vegetables are good sources of folate. However cooking of the vegetables caused a considerable decrease in the folate content of the vegetables. Considering that most leafy vegetables are consumed in their cooked form in Nigeria, preparation methods of traditional leafy vegetables that would allow for optimal retention of folate are necessary.
Support or Funding Information
This work was supported by an Agropolis Foundation grant for the internship of SIE and FWMD at Institut National de la Recherch Agronomique (INRA), Avignon, France. AWARD Fellowship provided the platform and opportunity of a 6‐month research attachment/ Advanced science training in INRA to conduct this research; University of Ibadan granted the permission to participate in the Advanced Science training during which this study was carried out. Labex Agro also supported this work.
Uncultivated/wild and cultivated traditional green leafy vegetables studied
Scientific name Family English name Local/common name Status
Amaranthus hybridus L.
Amaranthaceae
Pig weed
Efo tete/ green
Cultivated
Abelmoscus manihot (L.) Medikus (leaves and tender shoots)
Malvaceae
Okro leaves
Ilasa
Adansonia digitata d
Malvaceae
Baobab leaves
Luru / kuka
Uncultivated
Corchorus olitorius L.
Malvaceae
Jute mallow
Ewedu
Cultivated
Crassocephalum crepidioides (Benth.) S. Moore
Asteraceae
Ebolo
Uncultivated
Launaea taraxacifolia (Wild.) Amin, ex C. Jeffrey
Asteraceae
African lettuce/wild lettuce
Yanrin
Uncultivated
Solanum macrocarpon L.
Solanaceae
Efo igbagba
Cultivated/wild
Folate content of vegetables: RESULTS – Folate content of traditional green leafy vegetables
Vegetable Condition Moisture Folic acid Loss
Local/common name Scientific name % μg/100g %
Ewedu
Corchorus olitorius
Fresh
82.59
183.36±12.9
74.2
Boiled
95.13
47.31 ±3.7
Luru / kuka
Adansonia digitata
Dried
‐
149.64±13.9
88.4
Boiled
90.11
17.36±2.1
Okro/ ila
Abelmoscus esculentus fruit
Fresh
87.09
106.00±15.6
66.3
Boiled
95.77
35.69±8.49
Ilasa
Abelmoscus manihot
Fresh
77.05
46.75±9.49
n/a
Efo tete/ green
Amaranthus hybridus
Fresh
84.34
62.15±13.7
48.2
Boiled
91.58
32.19±4.9
Yanrin
Launaea taraxacifolia
Fresh
88.12
91.13±11.2
46.6
Boiled
92.16
48.63±8.4
Efo igbagba
Solanum macrocarpon
Fresh
84.82
21.54±3.1
60.6
Boiled
89.55
8.48±1.2
Ebolo
Crassocephalum crepidioides
Fresh
89.07
70.98±4.9
75.8
Boiled
94.1
17.18±1.7
... Various blanching techniques and their effects on different types of foods have also been described in the literature. Hot water blanching and its effect have been studied on almonds (Harris et al., 2012), paprika and chili (Schweiggert et al., 2005), mushrooms (Srivastava et al., 2009), beans, peas, broccoli, spinach, cauliflower, and carrots (Bureau et al., 2015). Effect of steam blanching has also been found for spinach (Bureau et al., 2015), kiwifruit (Llano et al., 2003), potato (Sotome et al., 2009), garlic slices (Fante & Norena, 2012), etc. Shivhare et al. (2009 investigated the blanching of carrots over a temperature range of 80-100 C in terms of peroxidase and catalase inactivation time and proposed time-temperature combinations of 7 min for 80 C, 85 C, and 90 C, and 5 min for 95 C. ...
... Hot water blanching and its effect have been studied on almonds (Harris et al., 2012), paprika and chili (Schweiggert et al., 2005), mushrooms (Srivastava et al., 2009), beans, peas, broccoli, spinach, cauliflower, and carrots (Bureau et al., 2015). Effect of steam blanching has also been found for spinach (Bureau et al., 2015), kiwifruit (Llano et al., 2003), potato (Sotome et al., 2009), garlic slices (Fante & Norena, 2012), etc. Shivhare et al. (2009 investigated the blanching of carrots over a temperature range of 80-100 C in terms of peroxidase and catalase inactivation time and proposed time-temperature combinations of 7 min for 80 C, 85 C, and 90 C, and 5 min for 95 C. They discovered that 95 C for 5 min was the optimal combination for minimizing vitamin C and β-carotene loss and maximizing the yield of carrot juice. ...
This paper presents an experimental and numerical study on the blanching and drying of carrots. Blanching of carrot slices has been performed at four temperature–time combinations. The effect of separating the core and cortex and blanching temperature on the drying rate of carrots has been studied. The blanching process increases the drying rate of carrots. The drying constant for slice, cortex, and core, respectively, has been found to be 22.84%, 24.90%, and 36.94% higher for the samples blanched at 95°C for 5 min, when compared to the unblanched samples. The drying rate also increases with the increase in blanching temperature. The drying constant increases by 37.64% and 109.18% in the case of cortex and core respectively, when compared to the slice. Temperature histories obtained through finite element analysis using ANSYS Fluent software were duly validated with the experiment.
Practical applications
The effect of separating the core and cortex and blanching temperature on the drying rate of carrots has been studied in this paper. The blanching process increases the drying rate of carrots. The drying rate also increases with the increase in blanching temperature. Blanching further also helps to improve the drying constant. The separation of the cortex and core from the slice also aids in reducing drying time and increasing the drying constant. Thus, it has been concluded that the novel concept of separating the slice into core and cortex combined with blanching resulted in a very significant increase in drying rate which will result in a great saving of time and power input in the drying process.
... Nambi et al. (2016) reported that the antioxidant activity in peeled beetroot increased by 10% with a higher temperature treatment due to the inactivation of oxidative enzymes. In addition, cooking could significantly increase indole-3acetonitrite (I3ACN) in the Brassicaceae vegetable family ( Bureau et al., 2015 ). ...
... Among cooking conditions, steaming would be the best for improving the scavenging activities based on both the DPPH and ABTS methods, particularly microwave steaming for the maximum cooking time. The highest scavenging activities using microwave steaming for the maximum cooking time could have been due to the extractability of antioxidant compounds in a covalently bound form with insoluble polymers ( Bureau et al., 2015 ). In addition, microwave cooking was fast and tended to improve the retention of total phenolics and flavonoids ( Wu et al., 2019 ). ...
Cooking affects the quality and bioactivity of vegetables. The effect was investigated of cooking conditions on the quality of Chinese kale subjected to either conventional boiling and steaming at 97 ± 2°C or microwave boiling and steaming at 900 W. Cooking by either conventional or microwave conditions increased (P≤0.05) the moisture content from 90.45% to 91.59–93.45%, but reduced the fiber content from 35.92 to 15.21–32.49% db and ash from 18.93% to 15.17–18.54% db. Either conditions could enhance the total phenolic content (TPC) from 1,605.21 to 1,634.69–2,013.57 mg GAE/100 g db and antioxidant activities of Chinese kale based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-3 ethylbenzothiazoline-6-sulphonic acid (ABTS) assays (P≤0.05). Extending the cooking time for 1–2 min increased the TPC and scavenging activity based on DPPH assay (P≤0.05). Steaming (615.75–794.72 mg TE/100 g db) by both conventional and microwave conditions produced higher scavenging activity based on DPPH assay than boiling (540.39–688.07 mg TE/100 g db). The maximum antioxidant activities based on DPPH (794.72 mg TE/100 g db) and ABTS (1,592.72 mg TE/100 g db) assays were obtained from microwave steaming at 900 W for 4 min. Both conventional and microwave cooking conditions reduced the lightness from 63.03 to 46.84–51.03 and hardness from 42.27 N to 24.38–38.11 N, but increased the greenness of the Chinese kale from (-)7.11 to (-)11.37– (-)12.98. Therefore, microwave steaming could be recommended for cooking greenish vegetables due to the health benefit from the increased antioxidant activity, convenience and similar cooked food composition, color and texture compared to conventional cooking.
... Two main mechanisms are described as being involved in folate losses, leaching into the surrounding liquid and oxidation during heat treatment [35]. The effect of different processing methods on folate content using the most common plant origin sources, such as legumes, grain products, green leafy and other vegetables, has been studied in recent years [32,[36][37][38][39][40]. Delchier et al. [41] reviewed folate content and stability in fruit and vegetables under most studied processes such as boiling, blanching, steaming, freezing, canning and juicing. ...
... High folate losses were observed, inter alia, after canning (from 65% for spinach to 77% for chickpeas), boiling (from 25% for green peas to 70% for chickpeas) and blanching with the highest losses found for spinach (on average from 50% to 95% for hashed spinach). Bureau et al. [39] studied vegetable samples and found no significant folate losses after steaming or microwave heating. None of the thermal treatments applied in the present study caused as drastic folate losses as in the examples of vegetable processing mentioned before and none of the samples had losses exceeding 45%. ...
Common liver sources in European countries include cow, chicken, duck, lamb and pig. Despite its decreasing popularity, liver is possibly one of the most nutrient-dense foods, being rich in high-quality protein and low in calories. In animals, the liver is the storage organ for folate. In this study, the effect of different cooking methods on folate vitamers content in chicken liver was investigated. Three folate derivatives, 5-CH 3-H 4 PteGlu, H 4 PteGlu and 5-HCO-H 4 PteGlu, were identified in the analyzed samples using high performance liquid chromatography (HPLC). The folate content in liver after sous-vide (60 • C/75 min) and steaming (100 • C/30 min) did not differ significantly (p ≤ 0.05) from raw liver folate content (781 µg/100 g). Even liver cooked in a combi oven or grilled (which resulted in significant folate losses) showed much higher folate content, 455-631 µg/100 g and 612-715 µg/100 g, respectively, than the most folate-abundant plant foods. These findings are important as they demonstrate that processed liver has the potential to improve the supply of folate and meet the recommended daily requirements, particularly when folate deficiency is common worldwide.
... These components are used to evaluate quality attributes because of their impact on taste. The intensity of soluble solid losses that occur during processing vary depending on factors including species, surface and size of the vegetables and types of cuts, temperature and time treatment, heat treatment system and proportion of water (Bureau et al., 2015;Nugrahedi, Verkerk, Widianarko, & Dekker, 2015;Armesto, Gómez-Limia, Carballo, & Martínez, 2016;Murador, Mercadante, & de Rosso, 2016). ...
... In other study, the lowest ascorbic acid content after cooking was found for stir-frying and boiling, while the lowest losses were caused by microwaving and steaming (Xu et al., 2014). Bureau et al. (2015) pointed out that microwaving was better for conserving the ascorbic acid in different vegetables than steaming, boiling and pressure-cooking. However, according to Zhong, Dolan, and Almenar (2015), microwaving leads to lower ascorbic acid content than both steaming and microwave steaming (in bags). ...
Brassica spp. are excellent sources of bioactive compounds. These vegetables are usually processed in the home, or by catering and food service industries, on the basis of convenience and taste preference. Shelf-life of these seasonal, perishable vegetables can be extended by preservation methods (e.g. freezing and canning), which usually involve blanching. Cooking, blanching, freezing and canning alter the physical and chemical characteristics of Brassica, and only some of the changes are desirable. We have reviewed the results of a large number of studies that assessed the effects of different treatments and storage conditions on various quality parameters in Brassica. These effects are important in relation to nutritional value, health benefits and attractiveness of the vegetables. The findings vary considerably for each bioactive component, depending on the treatments, conditions and matrices. Optimization of processing and storage conditions is, therefore, important to maximize the intake of beneficial compounds contained in Brassica spp.
... The difference in folate content of fresh and boiled samples were found to be statistically significant for all TGLVs (p<0.05). Studies have shown that folates are prone to losses by leaching when in direct contact with water (Bureau et al., 2015;Delchier et al., 2013Delchier et al., , 2012. Delchier et al. (2012) reported that when spinach and green beans were boiled in water, there was a > 50% loss of folate from the vegetables. ...
... Delchier et al. (2012) reported that when spinach and green beans were boiled in water, there was a > 50% loss of folate from the vegetables. Our findings are within the range for folate loss in boiled vegetables in previous literature (up to 94%) (Bureau et al., 2015, Delchier et al., 2012, Holasova et al., 2008. Given that most leafy vegetables are consumed in their cooked form in Nigeria, preparation methods of TGLVs that would allow for optimal retention of folate are necessary. ...
... Moreover, beetroot that was incorporated in the cereal-legume-vegetable formulation was first thermally processed by pressure-cooking. In fact, pressure-cooking is known to enhance the retention of nutrients such as vitamin A and C [28]. ...
... Similarly, the protein content of M1 was superior to that of bars developed in other studies. For instance, Rafiu et al. [25] and Torres et al. [28] both noted considerably lower protein content for their cereal bars with estimated values of 0.05% and 3.38-4.04% respectively. ...
With the globalization of food trade, we are observing tremendous changes in eating patterns of youngsters. Snack bars represent convenient, appropriately portioned, Ready-To-Eat food items, which not only supply nutrients to the body but also provide a feeling of satiety. The aim of this study was to formulate a novel high-protein, low Glycemic Index and low-fat snack bar that can be eaten on-the-move. Twelve different pulse-based bar formulations were developed and 85.1% of sensory panelists indicated that they particularly liked the taste of formulation M1. Since M1 contained peanuts, a nut-free and date-free equivalent (mM1) was developed to cater for individuals with allergies to these ingredients. A dehydrated mix (DM) based on the mM1 composition, was also developed. The microbiological and sensorial shelf lives of the products were then determined during storage at either ambient (ca. 23 ℃) or refrigerated temperatures (ca. 4 ℃) by determining counts of aerobic bacteria and yeast and mold. Mean aerobic bacteria and yeast and mold counts of M1 fell in the range of 8.4–9.4 and 4.5–5.4 log cfu/g and 7.5–8.6 and 3.8–4.9 log cfu/g during storage at room and refrigerated temperatures respectively. Aerobic bacteria and yeast and mold counts were consistently higher under ambient storage. Since a microbial population density >7 Log CFU/g usually marks the onset of microbiological spoilage, the bars were estimated to have a microbiological shelf-life of
... Apart from their role in assisting enzyme-substrate reactions, their other functions are equally important. These findings are consistent with the results of previous Bureau et al. (2015). The Vitamin B9 content of the formulations varied significantly at (p<0.05) among the samples. ...
Poor complementary food and feeding had been shown to increase the morbidity and mortality among under-five children in developing countries in which Nigeria is not exempted. This study aimed at evaluating the Nutrients Composition of Acha -Based complementary food supplemented with soybean and sweet potato flour. Raw materials used for the formulated of the complementary were purchased from Erekesan market in Akure Local Government Area of Ondo State. Five (5) samples were formulated in different ratios of Acha (100:70:60:50:40), Soyabean (20:25:30:35) and Orange flesh sweet potato (10:15:20:25). Samples were subjected to chemical and instrumental analysis in line with standard method. The data obtained were statistically analyzed using ANOVA to test for the significant difference among means (P<0.05) using Statistical Package for Social Science (SPSS version 22). Finding shows that Moisture, crude fibre, and carbohydrate was significantly (p<0.05) higher in sample Awhile, Sample E was significantly (p<0.05) higher protein (18.42%) and fat (12.40%) compared to other formulated samples. The Moisture, crude fibre, and CHO was significantly (p<0.05) decreases with decreased in the quantity of Acha use in the formulation of the CFs while crude fat, Ash and protein increases with increase in the quantity of soybean incorporated in the formulations. Sample E is significantly (P<0.05) higher in vitamin B1, B3 and B9 compared with sample A. vitamin B1, B3 and B9 increases with increase in the quantity of soybean and OFSP. All the samples have appreciable amount of sodium, calcium, phosphorus, magnesium and potassium but, zinc and iron was low in the entire sample. Sample E was exceptional in all the minerals but significantly (p<0.05) lower in Zinc and iron. The mean sensory scores revealed that sample C was different in after taste, flavour, mouth feel, colour and overall acceptability. The mean scores increase with increase in the proportion of soybean and potato in the formulated complementary food samples in terms of all the sensory attributes tested. The scores showed that sample C had the highest acceptability by the panelists. The complementary foods had improved nutrients that can support optimal nutrition of undernourished children and other older people.
... Apart from their role in assisting enzyme substrate reactions, their other functions are equally important. These findings are consistent with the results of previous investigations by Bureau et al. (2015). The vitamin B9 content of the samples varied significantly (p<0.05) ...
... Different thermal processing methods exert varying effects on the nutritional properties and functional composition of food. For instance, cooking can dissolve water-soluble substances, such as soluble sugars (Yang et al., 2019), water-soluble vitamins (Bureau et al., 2015), and trace elements (Koplıḱ et al., 2004), in food, leading to a significant reduction in their content. Conversely, steaming does not bring the grains into direct contact with water, resulting in fewer effects on the water-soluble components of the food. ...
Aohan millet has been cultivated for 8000 years and has rich nutritional value, such as high‐quality fatty acids and amino acids. Thermal processing is a conventional approach to food preparation. However, the effect of thermal processing on the formation of flavor substances in millet has not been clarified. Therefore, in this study, the effects of three different thermal processing techniques, namely, steaming, stir‐frying, and puffing, on the amino acids, fatty acids, and volatile flavor substances of Aohan millet were investigated using high‐speed automatic amino acid analyzer, headspace solid‐phase microextraction method, combined with gas chromatography–mass spectrometry (HS‐SPME/GC–MS) and gas chromatography (GC) with Aohan millet from Inner Mongolia as the raw material. All three thermal processing methods notably reduced the levels of protein, starch, polyphenols, and flavonoids in Aohan millet when compared to the raw millet (p < .05). Amino acid and fatty acid contents demonstrated an increase in fried and puffed millet relative to steamed millet, with notable distinctions in amino acid and fatty acid contents between these two groups. Following the steaming process, there was a significant increase in the flavor compounds of Aohan millet, rising from 53 to 80, while this increase was not observed in the other two groups. The correlation analysis suggested that the formation of flavor compounds was predominantly influenced by the types and levels of amino acids. The study suggested that different heat treatments affected the amino acid, fatty acid, and more significantly flavor material content and composition of Aohan millet. In conclusion, steaming treatment could retain more nutrients and richer flavor substances; while puffing treatment would enhance amino acid and fatty acid content, which provides a fundamental basis for scientifically guided processing and rational culinary application of Aohan millet.
... Other authors reported similar results. Bureau et al. 32 studied several treatments and only the microwave cooking induced a clear degradation of BCAR. Considering the results from the present study, MW at 750 W and WC at 100°C were the treatment that most negatively affected BCAR and ACAR contents, respectively. ...
The effect of different cooking methods (boiling, baking, steaming and microwaving) on the colour and texture of carrots, and on carotenoid bioaccessibility, was investigated to identify the more “sustainable cooking” methods.
... During blanching the plant tissue is disrupted, making the organelles containing carotenoids more accessible and possibly accounting for the enhanced carotenoid extraction efficiency (Behsnilian & Mayer-Miebach, 2017). This phenomenon has also been reported by other authors (Bureau et al., 2015;Dutta et al., 2009;Palermo, Pellegrini, & Fogliano, 2014) for various fruits and vegetables such as broccoli, carrots and pumpkin. In addition to the tissue disruption, the denaturation of carotenoid-associated proteins during blanching is another key factor in improving carotenoid extraction. ...
... However, the low p-value related to the kinetic impact (thermal vs. diffusion) reflects the importance of the diffusion in the loss of vitamin B6 during hydrothermal treatment. This observation is supported by others which showed that blanching or cooking in water leads to a greater loss of water-soluble vitamins (folates and vitamin C) from small vegetables than culinary steaming or industrial blanching for durations of about 10 min or less [36,37]. For vitamin B6, similar results were described for cooked meat [19]; however, fewer results are documented for fruits, vegetables, or legumes. ...
Chickpeas are more sustainable than other food systems and have high a nutritional value, especially regarding their vitamin composition. One of the main vitamins in chickpeas is vitamin B6, which is very important for several human metabolic functions. Since chickpeas are consumed after cooking, our goal was to better understand the role of leaching (diffusion) and thermal degradation of vitamin B6 in chickpeas during hydrothermal processing. Kinetics were conducted at four temperatures, ranging from 25 to 85 °C, carried out for 4 h in an excess of water for the diffusion kinetics, or in hermetic bags for the thermal degradation kinetics. Thermal degradation was modeled according to a first-order reaction, and diffusion was modeled according to a modified version of Fick’s second law. Diffusivity constants varied from 4.76 × 10−14 m2/s at 25 °C to 2.07 × 10−10 m2/s at 85 °C; the temperature had an impact on both the diffusivity constant and the residual vitamin B6. The kinetic constant ranged from 9.35 × 10−6 at 25 °C to 54.9 × 10−6 s−1 at 85 °C, with a lower impact of the temperature. In conclusion, vitamin B6 is relatively stable to heat degradation; loss is mainly due to diffusion, especially during shorter treatment times.
... Carotenoids extractability may be influenced by cooking. Additionally, the difference in the retention of carotenoids in cooked plants might be attributed to the loss of carotene caused by dripping during the cooking process (Bureau et al., 2015). ...
Indigenous edible plants are important components of food systems that are linked to food security and are important sources of nutrients with potential health benefits. Since knowledge about Thailand's various indigenous plants is limited, this study determined the nutritive values and bioactive compounds contained in eight edible indigenous plants growing within the conservation area of the Electricity Generating Authority of Thailand, Srinakarind Dam, Kanchanaburi province. Plant samples were analyzed as fresh or cooked (blanched or boiled) depending on customary preparation and consumption habits. Results showed that shoots and young leaves of Jang ( Maerua siamensis Kurz), Ta-Kuk ( Albizia lebbeck (L.) Benth), Pak-Wan-Pa ( Melientha suavis Pierre), and Som-kob ( Hymenodictyon exelsum Wall.) have potential health benefits in terms of nutritive values (vitamin C, dietary fiber, protein) and bioactive compounds (carotenoids, phenolic compounds, antioxidant activity). Shoots and young leaves of Jang were highest in protein, dietary fiber, phenolic compounds, and antioxidant activity. Shoots and young leaves of Ta-Kuk had the highest vitamin C level and considerable amounts of protein, dietary fiber, phenolic compounds, antioxidant activity, and carotenoids. Loss of vitamin C and bioactive compounds occurred most often in boiled plants rather than those that were blanched, though carotenoids increased with either boiling or blanching. This study's important findings should be translated into practical knowledge and disseminated to local communities and at the national level to encourage plant conservation, nutrition education, and the increased consumption of these indigenous plants.
... The baking process itself is also important. Significant losses under the influence of temperature and oxygen are widely reported in studies on the effects of various food processing on folate content in different foods [32,52,53,56,[61][62][63][64][65] including studies on the bread making process [10,59,60]. 21 14 In both types of bread, the addition of fresh kale and spinach caused a significant (P < 0.05) increase in folates (Table 4). ...
Bread is a staple food and can be a potential product to be enriched with various deficient nutrients. The objective of the study was to characterize the nutritional properties of toasted bread enriched with 10% and 20% of kale and wholemeal bread with 20% and 40% of spinach. The supplementation increased the phenolic content up to 2–3 times in the bread with the addition of 20% spinach and 40% kale. The highest antioxidant properties were noticed in extracts of bread with 20% kale. The in vitro digestion released the hydrophilic and lipophilic antioxidative compounds, leading to higher bioaccessibility of the breads enriched with these selected green vegetables. Even more than a 2-fold increase in folate content was observed in breads with the greatest addition of kale (20%) and spinach (40%), from 18.1 to 45.3 µg/100 g and from 37.2 to 83.2 µg/100 g, respectively, compared to the non-enriched breads. Breads with spinach showed significantly (P < 0.05) higher contents of all of the tested minerals, Cu, Mn, Fe, Zn, Mg, Ca, Na, K, and P, whereas kale enriched breads showed most of them. The results suggest that the addition of fresh green vegetables can enhance the daily supply of micronutrients and significantly increase the bioavailability of bioactive compounds with high antioxidant status.
... Limiting the contact between vegetables with water seems to be a possible approach to reduce folate loss during processing. Meanwhile, in previous research, it was reported that steaming does not significantly decrease the folate contents of spinach or broccoli (McKillop et al., 2002); steaming and microwave heating have slight impact on folate loss for studied frozen vegetable samples (Bureau et al., 2015). In the present study, boiling led to folate losses of 55 % and 35 % in sweet corn and waxy corn, respectively. ...
Fresh corn is a good source of micronutrients. Here, we investigated the effects of harvest time (18–24 days after pollination), storage temperature (25 °C, 4 °C, or −20 °C), and cooking method (boiling, steaming, or microwave heating) on folate content and retention in fresh corn. Folate levels in the selected six fresh corn cultivars were 66.6–152 μg/100 g fresh weight, with 5-methyltetrahydrofolate as the predominant vitamer; and the time of harvest did not significantly impact folate levels. An average folate retention of 83% was observed in waxy corn varieties after 5 days of storage at 25 °C, and 77% (average) of the folates was retained in sweet corn cultivars after 3 days of storage in a 4 °C refrigerator. The average folate retention was 71% after 14 days of storage at −20 °C, which decreased to 40% after 120 days. A folate reduction of 45% (average) was observed in boiled corn, whereas steaming and microwave heating involved minor folate loss of 12% and 15%. These results provide insight into folate contents and retention in raw and processed corn post-harvest. Our study revealed that fresh corn is rich in active folate vitamers and is thus a promising dietary source of folates.
... Folate retention has recently been studied in most common plant-derived sources, such as legumes, grain products, green leafy and other vegetables. Significant folate losses after cooking using different methods, such as steaming, blanching, boiling, microwaving, canning, or sous-vide cooking, reaching even up to 70-95% of initial folate content have been reported, both under domestic conditions and on an industrial scale [3,7,23,25,[60][61][62]. The current results showed a considerable difference in the stability of the two folate vitamers, 5-CH 3 -H 4 folate and 10-HCO-folic acid, during egg hard-boiling ( Table 3). ...
This study aimed to compare folate contents in hen eggs from four different farming systems, namely organic, free range, barn, and cage one. Folate retention during egg boiling was studied as well. The contents of individual folate vitamers were determined using the high-performance liquid chromatography method (HPLC), following trienzyme treatment. Folate content in eggs differed significantly (p < 0.05) due to the rearing system, with the highest mean content determined in the eggs from organic farming (113.8 µg/100 g). According to this study, one egg (60 g) may provide 40–86 µg of folates, which corresponds to 10–22% of the recommended daily intake for adults, 400 µg according to the Nutrition Standards for the Polish Population. The predominant folate form found in egg was 5-methyltetrahydrofolate, which showed considerably greater stability under boiling compared to 10-formylfolic acid present in a lower amount. In most eggs tested, the losses in total folate content did not exceed 15%. The color of yolk of the most folate-abundant organic eggs, had the highest value of lightness (L*) and the lowest value of redness (a*). This, however, does not correspond to consumer preferences of intense golden yolk color.
... Minimal processing such as blanching is known to alter the physical matrix of the vegetable by generally disrupting the leaf tissue cells making the organelles containing carotenoids be more accessible (Bédouet et al., 2015). In this study, blanching had a significant difference (P<0.05) on both β-carotene and vitamin C as the contents in blanched samples were lower by a range of 10-15% as compared to fresh leaves samples. ...
... We assume that due to the breakdown of plant cellular tissue, a higher content of carotenoids was released, subsequently extracted, and detected in the ensilaged samples compared to frozen or dried samples. 37,38 As the Bactozym inoculum did not further increase the carotenoid yield in the combined ensilaged + inoculated samples, it seems that microbial consortia present in the fresh samples were productive and competitive with the introduced microbes. ...
... If vegetables are eaten fresh, many of their nutrients are preserved; however, if vegetables are boiled, many water-soluble nutrients can be lost. Many nutrients, including vitamin C, thiamin, and folic acid, are sensitive to temperature (11). ...
Conducting and interpreting nutrition research involves consideration of the research question, study design, wide variability of nutrients in foods and dietary patterns, food environment, approaches used to collect and analyze dietary data, and manner in which results are reported. This article reviews all of these considerations with regard to diabetes-related nutrition research.
... Our findings only partly agree with previous research: although it is generally agreed that cooking produces significant losses in ASC and that boiling is more detrimental than steaming [27][28][29], microwave cooking (without water) has been reported to produce a high ASC degradation [28]. Bureau et al. [30] observed that the ASC retention was 77%, 94% and 88% for the boiled, steamed and microwaved cauliflowers, respectively, demonstrating that major losses in boiling were due to the dissolution into the boiling water. ...
This study investigates the effects of three cooking methods (boiling, steaming and microwaving) on the nutritional and physical properties of cauliflowers, carrots and sweet potatoes; e-senses were applied to interpret the sensory characteristics according to physico-chemical aspects. The nutritional quality was evaluated by determining the concentrations of key components and the antioxidant activity; e-sense data, combined with texture parameters, were processed by a principal component analysis. The cooking method and time significantly influenced the quality of the three products. Boiling, which detrimentally affected ascorbic acid, total phenolic concentration and antioxidant activity, enhanced carotene accessibility. Steaming produced losses in ascorbic acid, increasing total phenolics and carotenoids. Microwaving resulted in minor changes in ascorbic acid concentrations, preserved carotenoids and increased total phenolics. The nutritional quality was better preserved or enhanced using shorter cooking times. The elaboration of the data collected by the e-senses showed a clear evolution according to the cooking method and time. The results helped to determine the cooking method that best preserves the nutritional properties of the vegetables, highlighting the applicability of rapid instrumental methods to interpret the evolution of sensory characteristics.
... Folate loss after various treatments is presented in Table 1. The Pasteurization 0-16% (tomato puree, 0-15%, milk, 0-16%) [46][47][48] Oven-baking 14-46% (potato, 37%; rainbow trout, 30%; pollack, 46%; chicken, 34%; fortified bread, 14-25%) [35,[49][50][51][52] Chill þ reheating 14-36% (steamed/mashed potato, 14-36%) [53,54] Frozen þ reheating 7-50% (ready-to-eat meals, 7-50%) [ highest losses of folates were above 90% for hashed spinach by boiling and blanching [31]. Canning [37][38][39][40][41][42] and soaking [43][44][45] also strongly affect folate contents, with the losses being 50-70% for spinach and 84% for cauliflower, respectively. ...
Folates play a key role in one-carbon metabolism and are beneficial in the prevention of neural tube defects, cardiovascular and neurodegenerative diseases. Fruits and vegetables, with high contents of folates, are mostly consumed after food processing. Hence, it is important to know the process of folate losses and the interaction between folate and co-solutes. The current knowledge on stability of folates in foods and interaction with biological molecules are presented in this review. Folates degrade under light, heat, oxygen, and acidic pH. Antioxidants allow better preservation of folates. Folates bind to proteins and alter protein structure under irradiation, while proteins improve the photostability of folates. Folates interact with nucleotides and induce DNA damage under irradiation. Reactions of folates with other food components such as reducing sugars, especially that fructose and glucose accelerate the degradation of folates. Additionally, future perspectives in this context are identified.
... Igwemmar et al. [22] reported 9.96 mg/25ml and 3.62 mg/25ml vitamin C levels after 15 minutes of thermal treatment in peppers and carrots respectively. These findings are consistent with the results of Bureu et al. [23] where levels of vitamin C in raw samples were significantly higher than those in cooked ones. ...
Vitamin C is important for the human body function. People usually fulfill their vitamin C needs with food intake. A supplement intake also exists when needed. Vegetables are rich in various phytochemicals, biologically active substances with beneficial health effects, and are daily sources of vitamins and minerals for the body. The vitamin C content of eight widely used vegetables was established with the use of two assays (NBS and DCPIP). Food processing i.e. boiling, steaming and microwaving was used to establish vitamin C retention in cauliflower, peppers (red and green), potatoes (yellow and red), carrots, cabbage, and eggplant. The results obtained suggest that the most suitable cooking technique in terms of vitamin C retention is steaming.
... Замораживать можно не все виды продукции. Пригодность овощного сырья для замораживания определяется особенностями сорта, местом произрастания, степенью зрелости и т. д. [1][2][3][4][5][6][7][8][9][10][11]. О пищевой ценности тыквенных овощей и целесообразности расширения ассортимента блюд из них в рационе информации достаточно, однако исследованиям замораживания тыквенных овощей в последние годы посвящено относительно небольшое количество работ [12][13][14][15][16][17][18][19][20][21]. ...
This study addresses the alterations in nutrients [calcium, iron, and vitamins C and E (VC and VE, respectively)] and cordycepin content, alongside its sensory appeal in Cordyceps militaris , subjected to five distinct cooking methods: boiling, steaming, roasting, microwaving, and deep-frying. A comparative analysis showed the notable decline in nutrient content across most cooking methods excluding deep-frying. In notable contrast, the content of VE was substantially amplified during deep-frying, thereby emphasizing its value in preserving nutrients. However, an exception was noted wherein VE content remained essentially unchanged in the microwaved samples. Notably, the cordycepin content in boiled C. militaris reduced significantly, contrastingly, an elevation in this content was recorded for steamed, microwaved, or deep-fried samples, with roasting producing a stable content comparable to raw samples. The principal component analysis further discerned the iron, VC, and cordycepin as primary influencers on raw and roasted C. militaris , signifying superior retention during roasting, whereas deep-fried samples were predominantly affected by the calcium and VE content. Observation on nutrient losses revealed that boiling, steaming, and microwaving were less efficacious, compared with roasting and deep-frying. Sensory evaluations inductively favored steaming as synonymous with the finest culinary attribute, whereas deep-frying ranked least favorably on the sensory scale. Consequently, the present study offers refined dietary advice for the consumption of C. militaris catered to specific demographic groups, deepening understanding of the effects of various culinary practices on its overall nutrient profile and organoleptic properties.
The present study investigates the impact of traditional and novel cooking techniques on the nutritional and bioactive profile of
Brassica oleracea, commonly known as kale. As a member of the Brassica family, kale is well known for its high nutritional value
and possible health benefits. However, it is crucial to remember that the cooking techniques can significantly impact the
nutritional profile of kale. Various cooking methods were applied to kale samples through controlled experiments. Traditional
techniques like boiling and steaming were compared with innovative approaches such as microwave cooking and vacuum
cooking. Soluble solids, which include sugars and other compounds, were used as indicators of nutritional change.
Additionally, the levels of vital bioactive components, such as vitamins, antioxidants, and phytochemicals, were analyzed to
assess the overall impact of cooking methods. Preliminary findings suggest that the choice of cooking method plays a pivotal
role in determining the extent of nutritional and bioactive alterations in kale. Traditional methods, such as boiling, exhibited
substantial losses of soluble solids and certain heat-sensitive nutrients. In contrast, novel methods like vacuum cooking
displayed better preservation of soluble solids and bioactive compounds. The study sheds light on the complex relationship
between cooking techniques and the nutritional integrity of kale. By exploring various methods, this review paper contributes
to understanding how culinary practices can be optimized to enhance the retention of vital nutrients and beneficial bioactive
components in kale. These findings hold practical implications for individuals seeking to maximize the health benefits of kale
consumption while enjoying its culinary versatility.
Micronutrient deficiency still occurs in sub‐Saharan Africa (SSA) despite the availability of several food resources, particularly fermented foods and vegetables, with high nutritional potential. Fermentation enhances the quality of food in several aspects. Organoleptically, certain taste, aroma, and textures are developed. Health and safety are improved by inhibiting the growth of several foodborne pathogens and removing harmful toxic compounds. Furthermore, nutrition is enhanced by improving micronutrient contents and bioavailability from the food, especially vitamin B content. However, during processing and before final consumption, many fermented foods are heat treated (drying, pasteurization, cooking, etc.) to make the food digestible and safe for consumption. Heat treatment improves the bioavailability of B‐vitamins in some foods. In other foods, heating decreases the nutritional value because some B‐vitamins are degraded. In SSA, cooked starchy foods are often associated with vegetables in household meals. This paper reviews studies that have focused fermented starchy foods and vegetable foods in SSA with the potential to provide B‐vitamins to consumers. The review also describes the process of the preparation of these foods for final consumption, and techniques that can prevent or lessen B‐vitamin loss, or enrich B‐vitamins prior to consumption.
Consumption of diets rich in fruits and vegetables, which provide some fat-soluble vitamins and many phytochemicals, is associated with a lower risk of developing certain degenerative diseases. It is well accepted that not only the parent compounds, but also their derivatives formed upon enzymatic or nonenzymatic transformations, can produce protective biological effects. These derivatives can be formed during food storage, processing, or cooking. They can also be formed in the lumen of the upper digestive tract during digestion, or via metabolism by microbiota in the colon. This review compiles the known metabolites of fat-soluble vitamins and fat-soluble phytochemicals (FSV and FSP) that have been identified in food and in the human digestive tract, or could potentially be present based on the known reactivity of the parent compounds in normal or pathological conditions, or following surgical interventions of the digestive tract or consumption of xenobiotics known to impair lipid absorption. It also covers the very limited data available on the bioavailability (absorption, intestinal mucosa metabolism) and summarizes their effects on health. Notably, despite great interest in identifying bioactive derivatives of FSV and FSP, studying their absorption, and probing their putative health effects, much research remains to be conducted to understand and capitalize on the potential of these molecules to preserve health.
The Middle Pleistocene is associated with a new level of technology, Mode 2, commonly called the Acheulean Culture. This appears in Africa and Western Asia, but only later in Europe and not at all in Asia. It appears to be an indicator of communication, if not actual migration, among these areas. Climate swings, particularly in Europe, suggest that some forms of shelter and clothing had been invented, but more direct evidence is scarce. Controlled fire appears about a million years ago, but what traces are found suggest it was not widely used. Hunting of larger animals is well documented in the Middle Pleistocene employing weaponry such as lances and throwing spears. Meat consumption appears to have increased in importance, especially in temperate Europe. Strangely, Asian populations did not follow the same behavioral trends.
Cooking at home has experienced a decline in many countries since the mid-20th century. As rates of obesity have increased, there has been an emphasis on more frequent home cooking, including its incorporation into several food-based dietary guidelines around the world as a strategy to improve dietary quality. With the recent trend towards the adoption of diets richer in plant-based foods, many consumers cooking at home may now be cooking plant foods such as vegetables, potatoes and pulses more often. It is, therefore, timely to explore the impact that different home cooking methods have on the range of nutrients (e.g. vitamin C and folate) and bioactive phytochemicals (e.g. carotenoids and polyphenols) that such plant foods provide, and this paper will explore this and whether advice can be tailored to minimise such losses. The impact of cooking on nutritional quality can be both desirable and/or undesirable and can vary according to the cooking method and the nutrient or phytochemical of interest. Cooking methods that expose plant foods to high temperatures and/or water for long periods of time (e.g. boiling) may be the most detrimental to nutrient content, whereas other cooking methods such as steaming or microwaving may help to retain nutrients, particularly those that are water-soluble. Dishes that use cooking liquids may retain nutrients that would have been lost through leaching. It may be helpful to provide the public with more information about better methods to prepare and cook plant foods to minimise any nutrient losses. However, for some nutrients/phytochemicals the insufficient and inconsistent research findings make clear messages around the optimal cooking method difficult, and factors such as bioaccessibility rather than just quantity may also be important to consider.
In this thesis the association between the Western diet & its main components, and the risk on bladder cancer was studied. Results indicate that higher adherence to the Western diet could increase bladder cancer risk, which might derive from high consumption of organ meat. Little evidence of an inverse association was found between fish consumption and bladder cancer risk. This thesis also highlighted the role of fats and oils in association with the bladder cancer risk, showing the protective effects of MUFAs (monounsaturated fatty acids) and adverse effects of higher intake of cholesterol on bladder cancer risk. Higher consumption of animal fat might be detrimental, while plant-based fats & oils and sunflower oil could be beneficial for bladder cancer prevention. The results of the present thesis could be applicable for the prevention of bladder cancer by providing guidelines in order to minimize the adherence to the Western diet and encourage people to follow a healthier diet (i.e., the Mediterranean diet).
The effect of boiling, steaming, microwaving, cooking in a combi oven and using the sous-vide method under tested thermal conditions on the various properties of broccoli and spinach was evaluated. It was found that sous-vide reduced the total phenolic content to the lowest level and was the gentlest treatment due to the DPPH scavenging ability of spinach and broccoli extracts. Moreover, for folates, sous-vide cooking preserved these vitamer contents better than boiling for both vegetables but did not retain the green color of broccoli, as determined by C* (color saturation) and h° (hue angle). In broccoli samples, folate losses caused by sous-vide, microwave and cooking in a combi oven did not exceed 30%. The smallest decrease in the color tone parameter (h*) of broccoli and spinach was observed after microwaving. The same processing in spinach resulted in the highest color saturation (C*), and for both vegetables, it ensured the best sensory properties for general appearance, consistency and color.
One of the problems of modern society is the increasing detrimental effect of reactive oxygen species (ROS) on the cellular structure of the human body - the so-called oxidative stress. Potatoes are eaten almost everywhere and can become a stable and cheap source of natural antioxidants in the human body, thereby providing a preventive effect against chronic non-infectious diseases (oncology, diabetes mellitus, diseases of the cardiovascular system). To reduce the technological cycle of production at public catering enterprises, peeled potatoes are used. Of significant interest is the change in the antioxidant activity and chemical composition of such semi-finished potatoes, depending on the packaging option and storage time. It was found that the analyzed potato samples grown on the territory of the Samara region of the Volzhsky district really have antioxidant activity. The concept of the grade of the analyzed raw material affects such indicators as the content of phenols, acidity and mass fraction of reducing sugars. The highest accumulation of phenol content (up to 15 mg (GAE) / 100 g IP) was observed in the potato varieties Zekura and Red Lady. The last sample also showed a high level of flavonoid content (23 mg K / 100 g IP). A high value of the restoring force was shown by the variety Zekura (1.40 mM Fe2+ / 1 kg IS). Of all the analyzed objects, it was possible to determine the antiradical activity only for potatoes of the Leoni variety. Average batches of peeled potatoes were stored in several versions – with and without packaging. Control points were set according to the terms and types of storage of potatoes. There was a sharp decline in vitamin C starting from the second storage options checkpoints. This can be explained by its instability under the influence of environmental factors (air oxygen, light, temperature, long storage time).
Main groups of sensory active compounds - glucosinolates, isothiocyanates, phenolics and sugars in 3 cultivars of broccoli, 5 of Brussels sprout, 3 of cauliflower, and 4 of kohlrabi, both raw and cooked, were analyzed and correlated with selected sensory traits. The differences in the concentration of these components were significant between different vegetables and also noticeable between cultivars of one vegetable. The bitterness of Brussels sprouts and broccoli was correlated with glucosinolates, though Brussel sprouts contained definitely higher concentration (>1 g/kg fw) of these substances than their concentration in broccoli (<0.3 g/kg fw), or other vegetables. A positive correlation between sugar concentration and general desirability was observed in Brussels sprouts (0.91 — raw), kohlrabi (0.53 — raw; 0.8 — cooked), and raw cauliflower (0.85). According to sensory analysis, the high correlation between sweetness level and general desirability was observed, however, sweetness intensity was not correlated with total sugars concentration. A lack of any correlation between phenolic content and taste was observed. The results of research in this work emphasized the diversity of investigated Brassica vegetables from both phytochemical and sensory point of view.
This chapter covers the chemical changes food processing and storage can produce on vitamins. The four fat-soluble vitamins and nine classically recognized water-soluble vitamins have been systematically treated featuring their chemical characteristics, their nutritional and biochemical functions, the human body dependence on these micronutrients, and very importantly, the chemical mechanisms by which they are degraded during food processing and storage. Although one of the main concerns of food processors is to avoid or minimize the destruction of these organic substances so important to human health, losses are still inevitable and one of the purposes of this chapter is to lay down through schemes, figures, and concise explanations the reactions and the influencing factors of the degradative process in an attempt to guide food technologists, food processors, and health scientists.
Fruits and vegetables are the best food sources of vitamin C. However, fruits and vegetables can be also sources of potentially harmful substances to the human body, nitrates being one of these. The aim of this study was to compare vitamin C and nitrates contents in selected fruits and vegetables from supermarkets and local farmers' markets. Samples of plums, strawberries, apples, spinach, red peppers, and tomatoes were chosen for analysis. Content of vitamin C and nitrates was analyzed by HPLC/DAD. The hypothesis was that local market fruits and vegetables contain more vitamin C and fewer nitrates than samples bought in supermarkets. Laboratory analyses showed that there were differences in vitamin C in the case of strawberries, tomatoes, and red peppers. The highest level of ascorbic acid was in red pepper samples (141 mg.100g-1). In the case of fruit, the highest content was in strawberries (70 mg.100g-1). As far as nitrates content is concerned, in three cases out of six, the fruit and vegetables we tested from farmers' markets contained lower concentrations of nitrates than those purchased at supermarkets and the hypothesis was accepted in these cases. There was no significant difference between the nitrate content of the local market and supermarket strawberries and red peppers. Tomatoes had significantly higher nitrate content when purchased at farmers' markets than at supermarkets. Leafy vegetables are considered to be the major source of nitrates, and this was confirmed by this study. The highest content of nitrates was in the spinach sample (2969 mg.kg-1). Among all fruit samples, strawberries had the highest nitrates levels (maximum 131 mg.kg-1). The results of this work showed that the content of ascorbic acid and nitrates differs significantly depending on the type of fruit or vegetables.
Un tiers de la population mondiale souffrirait d’une carence en micronutriments entraînant des conséquences à court et long terme sur la vie des individus. L’enrichissement des aliments est une des pistes de l’optimisation nutritionnelle visant à lutter contre ces carences, mais les conditions de son efficacité maximale restent à définir au regard de la biodisponibilitéréelle de ces micronutriments. L’impact de la structure des aliments sur la cinétique de digestion des macronutriments a été largement démontré. En revanche, en ce qui concerne les micronutriments, les études ne permettent pas toujours de distinguer les effets composition et structure de la matrice sur leur biodisponibilité. L’objectif principal de cette thèse est d’évaluer l’impact de la seule structure d’aliments réels sur le processus de digestion et la biodisponibilité des micronutriments.Quatre aliments de même composition mais de structures et textures variables ont été conçus et enrichis en micronutriments (lutéine et vitamines D, B9 et B12). La structure de la matrice alimentaire a effectivement influencé la biodisponibilité de la lutéine et des vitamines D et B9 chez l’Homme, et ce de manière quantitative et cinétique, apportant ainsi une preuve de concept. Les études in vitro ont permis de confirmer l’effet structure observé in vivo et d’étudier en détail la dégradation de la matrice alimentaire, la libération des micronutriments et donc leur bioaccessibilité.Ce travail souligne l’importance de l’effet matrice dans la digestion des aliments. Il suggère aussi que la compréhension fine des mécanismes de digestion pourrait permettre, à terme, la maîtrise du déroulement de la digestion par un design ciblédes aliments.
The use of microwaves is very widespread at the domestic level thanks to its speed and ease of use. The aim of this study was to compare cooking loss, rancidity and sensory differences for hamburger patties cooked in conventional versus microwave ovens. We also determined sensorial differences with the triangular test, comparing two products presented in threesomes, one that corresponded to a patty cooked in the microwave and the other in a conventional oven. Chicken, turkey, pork and beef patties were purchased commercially, cooked in a conventional oven and in microwaves. Cooking loss was calculated, rancidity and sensory differences were evaluated between patties of the same type of meat and cooked in the different oven types. Cooking loss was lower in patties cooked in microwaves compared to those cooked in conventional ovens. For both oven types, acidity and peroxide index increased with respect to raw ones. Acidity was higher in hamburgers cooked in conventional ovens and the peroxide index was higher in burgers cooked in microwaves, reaching 10.6 meq O2/kg. In sensory analysis, significant differences were found (p<0.05) between patties cooked in a conventional oven and in microwaves. It is a better option to cook patties in a conventional oven, because the peroxide index is smaller than in microwaves; and within types of patties, beef and pork are more stable against oxidation.
Though folates are sensitive to heat treatments, leaching appears to be a major mechanism involved in folate losses in vegetables during processing. The aim of our study was to study folate diffusivity and degradation from spinach and green beans, in order to determine the proportion of each mechanism involved in folate losses.
Folate diffusivity constant, calculated according to Fick’s second law (Crank, 1975), was 7.4 × 10−12 m2/s for spinach and 5.8 × 10−10 m2/s for green beans, which is the same order of magnitude as for sugars and acids for each vegetable considered. Folate thermal degradation kinetics was not monotonous in spinach and green beans especially at 45 °C and did not follow a first order reaction. The proportion of vitamers changed markedly after thermal treatment, with a better retention of formyl derivatives. For spinach, folate losses were mainly due to diffusion while for green beans thermal degradation seemed to be preponderant.
Brassica species are very rich in health-promoting phytochemicals, including phenolic compounds, vitamin C, and minerals. The objective of this study was to investigate the effect of different blanching (i.e., water and steam) and cooking (i.e., water boiling, steam boiling, microwaving, and stir-frying) methods on the nutrient components, phytochemical contents (i.e., polyphenols, carotenoids, flavonoid, and ascorbic acid), antioxidant activity measured by DPPH assay, and phenolic profiles of white cauliflower. Results showed that water boiling and water blanching processes had a great effect on the nutrient components and caused significant losses of dry matter, protein, and mineral and phytochemical contents. However, steam treatments (blanching and cooking), stir-frying, and microwaving presented the lowest reductions. Methanolic extract of fresh cauliflower had significantly the highest antioxidant activity (68.91%) followed by the extracts of steam-blanched, steam-boiled, stir-fried, and microwaved cauliflower 61.83%, 59.15%, 58.93%, and 58.24%, respectively. HPLC analysis revealed that the predominant phenolics of raw cauliflower were protocatechuic acid (192.45), quercetin (202.4), pyrogallol (18.9), vanillic acid (11.90), coumaric acid (6.94), and kaempferol (25.91) mg/100 g DW, respectively.
The first of a two-part review of the recent and classical literature reveals that loss of nutrients in fresh products during storage and cooking may be more substantial than commonly perceived. Depending on the commodity, freezing and canning processes may preserve nutrient value. The initial thermal treatment of processed products can cause loss of water-soluble and oxygen-labile nutrients such as vitamin C and the B vitamins. However, these nutrients are relatively stable during subsequent canned storage owing to the lack of oxygen. Frozen products lose fewer nutrients initially because of the short heating time in blanching, but they lose more nutrients during storage owing to oxidation. Phenolic compounds are also water-soluble and oxygen-labile, but changes during processing, storage and cooking appear to be highly variable by commodity. Further studies would facilitate the understanding of the changes in these phytochemicals. Changes in moisture content during storage, cooking and processing can misrepresent changes in nutrient content. These findings indicate that exclusive recommendations of fresh produce ignore the nutrient benefits of canned and frozen products. Nutritional comparison would be facilitated if future research would express nutrient data on a dry weight basis to account for changes in moisture. Copyright © 2007 Society of Chemical Industry
Five different varieties of cauliflower (Brassica oleracea L. ssp. botrytis); two white (cv. ‘Aviso’, ‘Dania’), one purple (cv. ‘Grafitti’), one green (cv. ‘Emeraude’) and one romanesco/green pyramidal (cv. ‘Celio’) cultivar have been studied. All samples were thermally processed and the effects on the levels of glucosinolates (GLS), total phenols (TP), total monomeric anthocyanins (TMA), l-ascorbic acid (l-AA) and antioxidant capacities (FRAP and ORAC) were investigated. Processing methods applied were: blanching (3 min), boiling (10 min) and steaming (10 min). Total GLS were significantly (p < 0.05) affected by processing with the highest losses, 55 and 42% on average, occurring for boiled and blanched samples, respectively. Significant effects were also noted for steaming, but to a lesser extent, i.e. 19% average reduction. Antioxidant-related parameters were similarly affected with average losses of 27, 33, 36 and 46% in boiled cauliflower and 16, 21, 22 and 28% in blanched for TP, FRAP, l-AA and ORAC, respectively. Blanching and boiling reduced TMA in purple cauliflower by 38 and 53%, respectively. Steaming affected the antioxidant-related parameters the least for all cultivars. l-AA was significantly reduced by 14% in all cultivars by steaming. Some differences in behaviour between cultivars were noted, especially between white and coloured cultivars for TP, FRAP and l-AA, but also for some GLS. The main losses were caused by leaching into the processing water.
Effects of microwave and conventional cooking methods were studied on total phenolics and antioxidant activity of pepper, squash, green beans, peas, leek, broccoli and spinach. Total phenolics content of fresh vegetables ranged from 183.2 to 1344.7 mg/100 g (as gallic acid equivalent) on dry weight basis. Total antioxidant activity ranged from 12.2% to 78.2%. With the exception of spinach, cooking affected total phenolics content significantly (p < 0.05). The effect of various cooking methods on total phenolics was significant (p < 0.05) only for pepper, peas and broccoli. After cooking, total antioxidant activity increased or remained unchanged depending on the type of vegetable but not type of cooking.
Lutein is one of the most widely found carotenoids distributed in fruits and vegetables frequently consumed. Its presence in human tissues is entirely of dietary origin. Distribution of lutein among tissues is similar to other carotenoids but, along with zeaxanthin, they are found selectively at the centre of the retina, being usually referred to as macular pigments. Lutein has no provitamin A activity in man but it displays biological activities that have attracted great attention in relation to human health. Epidemiological studies have shown inconsistent associations between high intake or serum levels of lutein and lower risk for developing cardiovascular disease, several types of cancer, cataracts and age-related maculopathy. Also, lutein supplementation has provided both null and positive results on different biomarkers of oxidative stress although it is effective in increasing macular pigment concentration and in improving visual function in some, but not all, subjects with different eye pathologies. Overall, data suggest that whereas serum levels of lutein have, at present, no predictive, diagnostic or prognostic value in clinical practice, its determination may be very helpful in assessing compliance and efficacy of intervention as well as potential toxicity. In addition, available evidence suggests that a serum lutein concentration between 0.6 and 1.05 micromol/l seems to be a safe, dietary achievable and desirable target potentially associated with beneficial impact on visual function and, possibly, on the development of other chronic diseases. The use of lutein as a biomarker of exposure in clinical practice may provide some rationale for assessing its relationship with human health as well as its potential use within the context of evidence-based medicine.
Folates, ascorbic acid (vitamin C) and lutein (antioxidant carotenoid) concentrations were determined after cooking (boiling and steaming) fresh, frozen and canned green beans (Phaseolus vulgaris) and spinach (Spinacea oleracea). The aim of this study was to qualify and quantify the loss of water soluble (folates and ascorbic acid) and lipid soluble (lutein) micronutrients in the cooked products and liquids and the canning liquor. In canned products, folates were found in the canning liquor. Boiling regardless of product reduced plant tissue folates and ascorbic acid but not lutein concentrations. Loss of folates during boiling occurred due to leaching (diffusion) and ascorbic acid due to temperature (heating). Steaming reduced ascorbic acid but not folate or lutein concentrations.
The content and bioaccessibility of carotenoids from different chili peppers were analysed and the effects of typical domestic processing were investigated. Peppers were analysed before and after cooking by conventional boiling (10min in 100°C water) and also following a freezing period of four months in a domestic freezer (-20°C). The content and bioaccessibility of the eight carotenoids quantified varied, depending on cultivar, species, colour and processing. Provitamin A carotenoids (β-carotene and β-cryptoxanthin) and capsanthin were present at highest concentrations in the samples before and after processing. In general, yellow and orange peppers were the best sources of lutein, zeaxanthin and neoxanthin. Xanthophyll carotenoids were more efficiently transferred to the micelles and, therefore, were also more bioavailable. Processing decreased the carotenoid content in certain samples; however, the micellar content was generally not lower for processed peppers; therefore the bioaccessibility of carotenoids from processed peppers is enhanced relative to unprocessed peppers.
The microbial, physical, sensory and nutritional quality changes of kailan-hybrid broccoli after industrial
boiling, steaming, sous vide (SV), microwaving (MW), SVeMW and grilling throughout 45 days at 4 �C
were studied. Boiling, SVeMW and MW induced the highest total colour differences. Boiling and
steaming produced the greatest stem softening. Based on the overall sensory quality, the commercial life
was established in 45 days, except grilling (14 days) and SV (21 days). Apparently, cooking increased
the total phenolic content up to 2.0 and 1.7-fold for grilling and MW, respectively, owing to
a better extraction. SVeMW, SV and MW produced the highest total antioxidant capacity increases
around 5.4e4.7-fold, contrary to the low enhancements of boiling and grilling (2.9-fold). The best
chlorophylls retention was attained by boiling. The total carotenoids content was enhanced up to 1.5e2-
fold. Conclusively, these treatments generally showed an excellent microbial reduction and nutritional
quality, which, in some cases, was enhanced after 45 days.
The effect of boiling and steaming on content of phytochemicals (carotenoids, chlorophylls, polyphenols and ascorbic acid) all evaluated by HPLC, total antioxidant capacity (TAC) measured by means of TEAC and FRAP assays and colour (L∗, a∗, b∗, C, H°) of three frozen vegetables (carrot, cauliflower and spinach) was evaluated. Steaming increased the content of polyphenols in all vegetables and limited the depletion of carotenoids in spinach. Accordingly, TAC remained unvaried or increased both for steamed carrot and spinach. Boiling had a more marked effect on nutritional pattern of frozen vegetables in comparison with steaming, leading to a general loss of phytochemical compounds and TAC for all vegetables. Ascorbic acid was detected only in cauliflower and decreased after both treatments. Colour of frozen vegetables was only slightly influenced by cooking, probably due to blanching pre-treatment. Slight decrements of redness (a∗) for carrot in relation with loss of carotenoids and greenness (−a∗) for steamed spinach, due to a significant loss of total chlorophylls, were observed.Steaming increased TAC and bioaccessibility of polyphenols in all frozen vegetables while boiling led to a general loss of carotenoids and phenolic compounds and a TAC decrease.
In this study, we analyzed the modifications of antioxidant activity consequent to 3 typical home cooking practices (steaming, boiling, and microwave cooking) in fresh and home frozen vegetables. Six different vegetable species were examined: carrots (Daucus carota L.), zucchini (Cucurbita pepo L.), tomatoes (Solanumn lycopersicum L.), green beans (Phaseolus vulgaris L.), peas (Pisum sativum L.), and yellow peppers (Capsicum annuum L.). All vegetables were conventional products and were analyzed in season to minimize differences due to agricultural practice and storage. Cooking and freezing are generally regarded as destructive to antioxidants, and this has fostered a belief among many consumers that raw vegetables are nutritionally superior to their frozen and/or cooked forms. In the current study, we provide evidence that this is not always the case.
The nutritional benefit of bioactive metabolites depends on their bioavailability, i.e. the proportion that leaves the food matrix, and crosses the enteral barrier to reach their cellular target. The present study focused on lycopene, the major and bioactive tomato carotenoid, the bioavailability of which is known to be enhanced in cooked products. To better understand how processing may facilitate lycopene release, we assessed whether hot-break (HB) or cold-break (CB) treatments influence the tomato lycopene bioaccessibility. HB and CB are used in the tomato industry to modulate texture of purees through endogenous cell-wall lytic enzymes activity. HB and CB processes were mimicked through microwave heating, leading to a differentiated temperature rise in the product. The HB and CB models led to the expected differences, i.e. more viscous puree for HB with low methanol. The ability of the tomato matrix to release lycopene was measured as the extractability of lycopene to oil under standardized mixing conditions. We expected that CB treatment, by enhancing cell-wall degradation, would lead to enhanced lycopene bioaccessibility. The opposite was observed: oil contained three times less lycopene when mixed by CB (around 0.3μgml(-1); similar to results obtained with fresh purees) than when mixed by HB (around 0.9μgml(-1)), although HB caused more lycopene degradation. Kinetics studies indicated that the quick rise of temperature at the beginning of HB treatment was a key parameter.
The effects of different cooking methods (boiling, frying and microwave cooking) on the antioxidant activity of some selected vegetables (peas, carrot, spinach, cabbage, cauliflower, yellow turnip and white turnip) were assessed by measuring the total phenolic contents (TPC), reducing power and percentage inhibition in linoleic acid system. TPC (gallic acid equivalents g/100 g of dry weight) and reducing power of the methanolic extracts of raw-, microwaved-, boiled- and fried vegetables ranged 0.333–2.97, 0.52–2.68, 0.48–2.08, 1.00–2.02 and 0.391–2.24, 0.822–1.10, 0.547–1.16, 0.910–4.07, respectively. The level of inhibition of peroxidation ranged 71.4–89.0, 66.4–87.3, 73.2–89.2 and 77.4–91.3%, respectively. Antioxidant activity of the vegetables examined was appreciably affected because of varying cooking treatments. TPC of vegetables, generally, decreased by boiling, frying and microwave cooking. There was a significant (P < 0.05) increase in reducing power as a result of frying. However, boiling and microwave cooking did not affect reducing power. Inhibition of peroxidation increased by boiling and frying, whereas, in contrast it was decreased by microwave cooking. The results of the present investigation showed that all the cooking methods affected the antioxidant properties of the vegetables; however, microwave treatment exhibited more deleterious effects when compared with those of other treatments. Thus an appropriate method might be sought for the processing of such vegetables to retain their antioxidant components at maximum level.
Lycopene is the principal pigment of the carotenoids naturally found in tomatoes and is important not only because of the color it imparts but also because of the recognized health benefits associated with its presence. Red tomatoes typically contain about 95% of their lycopene as the all-trans isomer, the most stable form. In tangerine tomatoes, on the other hand, the lycopene is present as tetra-cis-lycopene, a geometric isomer of all-trans lycopene. Lycopene is a major component found in blood serum. This carotenoid has been extensively studied for its antioxidant and cancer-preventing properties. Prevention of heart disease has been shown to be another antioxidant role played by lycopene because it reduces the accumulation of platelets that eventually lead to blood clots, heart attacks, and strokes. In contrast to many other food phytonutrients whose effects have only been studied in animals, lycopene from tomatoes has been repeatedly studied in humans and found to be protective against several cancers, which now include colorectal, prostate, breast, lung, and pancreatic cancers. This review outlines the background information dealing with lycopene and presents the most comprehensive and current understanding of its potential functional role in human health.
The effects of four culinary treatments (steaming and boiling in a covered pot, a pressure cooker or a microwave oven) on the chlorophyll a and b, all-trans-lutein, phaeophytin a and b and all-trans-β-carotene (provitamin A) contents of green beans (Phaseolus vulgaris, L.) were evaluated. The pigments in the fresh and treated beans were determined by gradient elution reverse-phase HPLC with UV detection. Boiling the beans in a covered pot, pressure cooking or microwaving them caused smaller losses of pigments than steamed cooking. Since pressure cooking also generally leads to smaller losses of nutritious components (e.g. vitamin C), it is recommended over the traditional method of boiling beans in a covered pot.
The following four vegetables; beans (Phaseolus vulgaris var. vulgaris), brinjal (Solanum melongena var. esculentum), knol-khol (Brassica oleracea var. caulorapa) and radish (Raphanus raphanistrum satvius) were processed either by conventional, pressure or microwave cooking methods and were analysed for their nutritional and sensory profile. Raw samples were used as controls. Microwave cooking resulted in greater moisture loss when compared with vegetables cooked by other methods. The protein, fat, total ash, calcium, phosphorus, iron, and dietary fibre contents of the vegetables did not differ significantly in raw or cooked vegetables. Ascorbic acid was destroyed to the greatest extent by pressure cooking followed by microwave and conventional method. The sensory attributes of cooked vegetables, as evaluated by a paired preference test, revealed that there were no significant differences between cooked radish and knol-khol but, in the case of beans and brinjal, microwave and conventionally cooked samples were preferred over pressure cooked ones.
In this second part of our review, we examine the literature for changes in carotenoids, vitamin E, minerals, and fiber due to processing, storage, and cooking of fresh, frozen, and canned fruits and vegetables. While inconsistencies in methodology and reporting methods complicate interpretation of the data, the results show that these nutrients are generally similar in comparable fresh and processed products. The higher levels of carotenoids typically found in canned as compared to fresh products may be attributed to either reporting results on a wet rather than dry weight basis, greater extractability, or differences in cultivars. There are relatively few studies on processing, storage, and cooking effects on vitamin E in fruits and vegetables. Further research is needed to understand nutritional changes in those few fruits and vegetables rich in vitamin E, such as tomatoes. Minerals and fiber are generally stable to processing, storage, and cooking, but may be lost in peeling and other removal steps during processing. Mineral uptake (e.g., calcium) or addition (e.g., sodium) during processing can change the natural mineral composition of a product. Sodium concerns in canned food can be addressed by choosing products with no salt added. Since nutrient content varies considerably by commodity, cultivar, and postharvest treatments, inclusion of a wide variety of fruits and vegetables in the diet is encouraged. Copyright © 2007 Society of Chemical Industry
The investigation concerned frozen broccoli produced using a traditional method, i.e. from the raw material blanched before freezing, and a modified method of freezing cooked broccoli. In comparison with blanched broccoli the material cooked before freezing contained more dry matter, carotenoids and beta-carotene and less vitamin C and polyphenols; its antioxidative activity was also poorer. In frozen products stored for 0, 4, 8 and 12 months at − 20 or − 30 °C and then cooked, a steady decrease was observed in the content of all the constituents. Compared with the raw material cooked broccoli stored for 12 months contained 29–33% of vitamin C, 54–66% of polyphenols, 80–97% of carotenoids, 69–80% of beta-carotene and showed a 29–35% decrease in the antioxidative activity. A higher or similar level of the above properties was found in samples cooked before freezing as compared with blanched goods; a higher level was ascertained in samples stored at − 30 °C compared with those stored at − 20 °C. The same sensory quality was found for frozen goods obtained with both methods. Frozen products and ready-to-eat frozen products stored at − 30 °C had higher sensory quality.Industrial relevanceReady to eat vegetable products are more and more popular among individual consumers and catering services. The present work compared quality of traditional frozen broccoli and ready to eat frozen broccoli, both prepared for consumption. After long term frozen storage a higher or similar level of antioxidants was found in ready to eat type as compared with traditional type, and sensory quality of both types was at least good. Products stored at − 30 °C retained more antioxidants and revealed better sensory quality than ones stored at − 20 °C.
The bioavailability of all-trans-β-carotene from vegetables depends among other things on the molecular linkage and the food matrix in which it is incorporated. It is assumed that cooking can increase the bioavailability by disruption of the plant cell wall and releasing from protein complexes. But it can also lead to isomerization and degradation of all-trans-β-carotene. In this investigation the influence of different domestic cooking methods on the all-trans- and cis-β-carotene as well as the α-tocopherol content in fresh and frozen broccoli and red sweet pepper is examined. While in fresh broccoli all cooking methods lead to a significant release of all-trans-β-carotene and α-tocopherol in the frozen broccoli no change or a decrement occurs. In the fresh and frozen peppers no change or a significant loss of α-tocopherol and all-trans-β-carotene is observed. A slight increase in the cis-isomers of β-carotene can only be found by cooking fresh broccoli.
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.
Three mushrooms, Clitocybe maxima, Pleurotus ferulae and Pleurotus ostreatus grey strain were used to study their flavour components and antioxidant properties. The volatile flavour components found comprised of six eight-membered carbon compounds and two aromatic compounds. The content total of soluble sugars and polyols was 125–270 mg/g. The content of monosodium glutamate-like components was 1.76–8.89 mg/g. The contents of flavour 5′-nucleotides ranged from 1.89 to 7.59 mg/g. Based on the results obtained, three mushrooms possessed highly intense umami taste. Ethanolic extracts were more effective in the inhibition of conjugated diene and scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals, whereas hot water extracts were more effective in the scavenging ability of hydroxyl radicals. EC50 values were less than 14 and 30 mg/ml for ethanolic and hot water extracts, respectively, indicating that the three mushrooms were relatively effective as they exhibited antioxidant properties, despite having scavenging abilities for hydroxyl radicals. Phenols were the major antioxidant components and the total contents were 5.10–11.1 mg gallic acid equivalents/g.
This study evaluated the effect of common cooking practices (i.e., boiling, microwaving, and basket and oven steaming) on the phytochemical content (carotenoids, chlorophylls, glucosinolates, polyphenols, and ascorbic acid), total antioxidant capacity (TAC), and color changes of three generally consumed Brassica vegetables analyzed fresh and frozen. Among cooking procedures, boiling determined an increase of fresh broccoli carotenoids and fresh Brussels sprout polyphenols, whereas a decrease of almost all other phytochemicals in fresh and frozen samples was observed. Steaming procedures determined a release of polyphenols in both fresh and frozen samples. Microwaving was the best cooking method for maintaining the color of both fresh and frozen vegetables and obtaining a good retention of glucosinolates. During all cooking procedures, ascorbic acid was lost in great amount from all vegetables. Chlorophylls were more stable in frozen samples than in fresh ones, even though steaming methods were able to better preserve these compounds in fresh samples than others cooking methods applied. The overall results of this study demonstrate that fresh Brassica vegetables retain phytochemicals and TAC better than frozen samples.
Carotenoids are studied for their role as pigments and as precursors of aromas, vitamin A, abscisic acid, and antioxidant compounds in different plant tissues. A novel, rapid, and inexpensive analytical protocol is proposed to enable the simultaneous analysis of four major tomato carotenoids: lutein, lycopene, beta-carotene, and phytoene. Microextraction is performed in the presence of sodium chloride, n-hexane, dichloromethane, and ethyl acetate on fresh tomato powder that has been finely ground in liquid nitrogen. The carotenoids are extracted by agitation and centrifugation and then analyzed by HPLC using a diode array detector. The principal advantage of this extraction resides in the absence of an evaporation step, often necessary to assay tomato carotenoids other than lycopene. Whatever the carotenoid, tests for accuracy, reproducibility, and linearity were satisfactory and indicative of the method's reliability. The stability of extracts over time (several days at -20 degrees C) as the satisfactory sensitivity of the assay whatever the fruit ripeness had a part in the robustness of the method. Reliable, rapid, simple, and inexpensive, this extraction technique is appropriate for the routine analysis of carotenoids in small samples.
In this study, we analyzed the modifications of antioxidant activity consequent to 3 typical home cooking practices (steaming, boiling, and microwave cooking) in fresh and home frozen vegetables. Six different vegetable species were examined: carrots (Daucus carota L.), zucchini (Cucurbita pepo L.), tomatoes (Solanumn lycopersicum L.), green beans (Phaseolus vulgaris L.), peas (Pisum sativum L.), and yellow peppers (Capsicum annuum L.). All vegetables were conventional products and were analyzed in season to minimize differences due to agricultural practice and storage. Cooking and freezing are generally regarded as destructive to antioxidants, and this has fostered a belief among many consumers that raw vegetables are nutritionally superior to their frozen and/or cooked forms. In the current study, we provide evidence that this is not always the case.
Since humans cannot synthesise carotenoids de novo, we depend upon the diet exclusively for the source of these micronutrients. Although the necessity for beta-carotene, as the precursor of vitamin A has been recognised for many years, it is lycopene that has attracted substantial interest more recently. Lycopene is the red-coloured carotenoid predominantly found in tomato fruit, but in few other fruits or vegetables. It has claimed that it may alleviate chronic diseases such as cancers and coronary heart disease. This possibility has been studied extensively, by epidemiological studies and biochemical investigations of its properties and its bioavailability from tomato-based diets. This article summarises the current state of knowledge of the properties of lycopene, its possible role in human health and areas for future research.
Lutein is a human serum carotenoid which is not synthesized by humans and thus must be obtained by the ingestion of food containing it such as fruits and vegetables. Lutein is present in different forms in those foods as all-trans-lutein, cis-lutein, epoxi-lutein, and lutein linked to proteins. It discusses if the intake of lutein or diets supplemented with lutein or diets rich in fruits and vegetables are important in the prevention of diseases like some cancers, cardiovascular diseases, etc., that may be affected by the antioxidant effect of lutein; or in the prevention of age-related macular degeneration and other eye diseases. The concentration of lutein in fruits and vegetables depends on the species. We've included the concentration of lutein in 74 species reported by different authors since 1990. Currently the quantification of lutein is mainly performed by HPLC, but more investigations into a quantification method for lutein, lutein isomers, and epoxi-lutein are necessary. Improvement of lutein extraction methods is important as well. Methods commonly used in the vegetable and fruit industry like heat treatment, storage conditions, etc. can change lutein concentrations; other factors depend on the plant, for instance the variety, the stage of maturity, etc.
We present a technique for easy, rapid analysis of both total and reduced forms of vitamin C in fruits using microplates and a plate reader. This technique has been compared with a spectrofluorometric technique classically used for assaying vitamin C in fresh tomato. We have applied these methods to a population of 118 tomato mutant lines and controls in search of variability for this trait. Six lines, identified as having high vitamin C levels, and four lines having low vitamin C levels have been chosen for further study. The vitamin C levels have been compared with sugar concentration, dry matter content, fruit weight, titratable acidity, and firmness. The correlations that often exist in tomato varieties between sugar and vitamin C content (positive correlation) or fruit weight and vitamin C content (negative correlation) can be uncoupled in the lines selected for further analysis.
The objective of the present study was to evaluate the effect of three common cooking practices (i.e., boiling, steaming, and frying) on phytochemical contents (i.e., polyphenols, carotenoids, glucosinolates, and ascorbic acid), total antioxidant capacities (TAC), as measured by three different analytical assays [Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP), ferric reducing antioxidant power (FRAP)] and physicochemical parameters of three vegetables (carrots, courgettes, and broccoli). Water-cooking treatments better preserved the antioxidant compounds, particularly carotenoids, in all vegetables analyzed and ascorbic acid in carrots and courgettes. Steamed vegetables maintained a better texture quality than boiled ones, whereas boiled vegetables showed limited discoloration. Fried vegetables showed the lowest degree of softening, even though antioxidant compounds were less retained. An overall increase of TEAC, FRAP, and TRAP values was observed in all cooked vegetables, probably because of matrix softening and increased extractability of compounds, which could be partially converted into more antioxidant chemical species. Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a cooking method would be preferred to preserve the nutritional and physicochemical qualities.
Quality changes after vacuum-based and conventional industrial cooking of kailan-hybrid broccoli throughout retail cold storage
- G B Martínez-Hern Andez
- F Art Es-Hern Andez
- P A Omez
- F Art Es
Martínez-Hern andez, G. B., Art es-Hern andez, F., G omez, P. A., & Art es, F. (2013).
Quality changes after vacuum-based and conventional industrial cooking of
kailan-hybrid broccoli throughout retail cold storage. LWT e Food Science and
Technology, 50, 707e714.