Thirty-five fruits and seventeen vegetables from Martinique were evaluated for total phenol content (TPC), Vitamin C and carotenoid content. TPC, Vitamin C and carotenoid contents ranged from 11.7 to 978.6 mg/100g, 0.1 to 2853.8 mg/100g and 9.7 to 9269.7 μg/100g respectively. Fruits and vegetables from Martinique have equivalent or higher TPC, Vitamin C and carotenoid contents than fruits and vegetables from temperate climates. Cashew apple had high values for all three parameters (55.8 mg/100g of Vitamin C, 603 mg/100g of TPC and 924 μg/100g of carotenoids). Bassignac mango and mamey apple had the highest carotenoid contents, with 3800.3 and 3199.7 μg/100g respectively. Acerola had the highest Vitamin C and polyphenol contents with 2853.8 μg/100g and 727.4 mg/100g respectively. Pigeon peas had high values for all three parameters (569.2 mg/100g of Vitamin C, 978.6 mg/100g of TPC and 364.3 μg/100g of carotenoids). Pumpkin and watercress had the highest carotenoid content, with 9269.7 and 4339 μg/100g respectively. TPC, Vitamin C and carotenoid content were significantly impacted by processing techniques. TPC, Vitamin C and carotenoid contents decreased by up to 75.78%, 100% and 70.18% respectively, depending on the processing technique used.
Fruits and vegetables provide an optimum mix of antioxidants, such as Vitamin C, polyphenols and carotenoids [
The impact of processing methods on tropical fruits and vegetables has been little studied. This impact on nutrients from temperate fruits and vegetables is a little known. For broccoli, there was an influence of cooking mode, with a loss of 97% of flavonoids for microwave-cooked florets, whereas steaming had less significant effects [
In this study, selected tropical fruits and vegetables from Martinique were analyzed in order to highlight their nutritional qualities and health benefits and assess the impact of processing, with the ultimate aim being to promote local plant biodiversity. To carry out the study it was necessary to obtain nutritional information for Martinique-grown tropical plants in terms of total polyphenol, Vitamin C and carotenoid contents. In addition, the impact of transformation processes on the nutritional quality of six fruits and vegetables (mamey apple, pumpkin, mandarin, okra, sweet potato and christophine) had to be established.
The varieties selected are representative of varieties cultivated in Martinique. A representative sample was obtained from local markets. Samples were collected from a selection of thirty-five fruits and seventeen vegetables, taking into account geographical and varietal diversity, ratio of production and seasonality. A minimum of 30 pieces for each fruit and vegetable were collected for analysis.
The protocol was applied to the physicochemical characterization of each variety. Preparations were made using pilot equipment. Raw material was treated as it is consumed in Martinique. Fruits were peeled and seeded if necessary, the pulp collected and crushed or pressed and then filtered according to the fruit in question. Vegetables were peeled if necessary and steamed, depending on vegetable type. The samples obtained were frozen and stored at −18˚C in sealed plastic bags pending analysis.
Total polyphenols were determined using Folin and Ciocalteu’s method described in Georgé et al. [
Total carotenoids were determined using a colorimetric method. 2 g of samples were extracted for 30 minutes with 50 mL of a ternary solvent (hexane/ethanol/acetone 50/25/25). After filtration (Whatman), solvent was washed three times with 25 mL distilled water. Absorbance at 450 nm was determined using a spectrophotometer (JENWAY 7305). Results were obtained using the Beer-Lambert law and expressed in µg/100g.
Vitamin C was measured using the K-ASCO 11/05 Megazyme kit. 100 µL of samples were incubated for 3 min at 37˚C with phosphate/citrate buffer and ascorbic acid oxidase. 200 µL of tetrazolium salt were added and incubated for 3 min at 37˚C. 200 µL of reactive agent were added and absorbance at 578 nm was immediately read using a spectrophotometer (JENWAY 7305). Results were obtained using the Beer-Lambert law and expressed in µg/100g. The recommended daily intake determined by the World Health Organization is about 60 mg.
For temperate fruits and vegetables, data was based on the worldwide food composition tables.
Raw material processing was performed according to the suitability of the plant (crisps, canned in syrup, fresh- cut packaged, filtered pasteurized pure juice, flour, frozen or steamed). Treatment of plants was carried out with pilot equipment from the institute’s technological hall. All fruits and vegetables were washed, sanitized and peeled before processing.
Vegetables were cut into pieces of 2 - 4 mm thickness in a BIRO cubing machine and cooked at 110˚C/100% relative humidity in a FRIMA steam oven until a core temperature of 90˚C was reached. Pieces were then ground for 3 min at 1500 rpm with a STEPHAN UM44. Samples were frozen in an ACFRI freezing cell and stored at −18˚C before analysis.
Vegetables were cut into pieces of 2 mm thickness using a slicing machine. Slices were then immersed in sunflower oil at 120˚C and −0.85 bar for 400 seconds in a FEMAG vacuum fryer. After frying, the product was drained on paper and centrifuged for 30 seconds to dry and remove excess oils. Samples were ground for 3 min with a STEPHAN UM44 and stored at ambient temperature before analysis.
Vegetables were grated into 2 mm thick pieces with a ROBOT-COUPE slicing machine. Samples were ground for 3 min with a STEPHAN UM44 and frozen at −18˚C before analysis.
400 g of fruits were added to 300 mL of syrup (20˚ Brix, pH 4.5, 75˚C) in 4/4 cans. Cans were sealed with a BERTUZZI sealer and sterilized in a BARRIQUAND autoclave for 20 - 30 min at 100˚C - 115˚C. Vegetables were blanched for 2 min at 100˚C in an AURIOL cooking pot. They were then placed in 4/4 cans with blanching water at 70˚C added with 10 mg/g salt and 2 mg/g citric acid. Cans were sealed with a BERTUZZI sealer and sterilized in a BARRIQUAND autoclave for 20 - 30 min at 100˚C - 115˚C. All cans were then opened and pro- ducts were ground for 3 min at 1500 rpm in a STEPHAN UM44. Samples were frozen in an ACFRI freezing cell and stored at −18˚C before analysis.
Mandarins were peeled and sliced prior to pressing with a BERTUZZI hydraulic press. Juice was filtered and then stored at −18˚C before analysis. For pasteurized juice, juice was pasteurized in a BERTUZZI pasteurizer (heat treatment 90˚C for 4 min) and then stored at −18˚C pending analysis.
Sweet potatoes were cut into thin 2 mm thick slices in a slicing machine and dried for 24 hr at 50˚C, 40% relative humidity and 70% ventilation in a FEMAG drier. Dried slices were ground for 3 minutes at 1500 rpm in a STEPHAN UM 44 and then passed through a 300 µm sieve with a SAMAP mill. Flour was stored at ambient temperature before analysis.
Vegetables were cut into 2 - 4 mm thick slices in a slicing machine, blanched for 2 minutes in a FRIMA steam oven at 90˚C 100% relative humidity, ground for 3 min at 1500 rpm in a STEPHAN UM 44 and frozen at −18˚C in an ACFRI freezing cell and stored at −18˚C before analysis.
The physical and chemical mean values of triplicate measurements or analysis were statistically analysed. Ana- lysis of Variance (ANOVA) based on Student Test, Principal Component Analysis (PCA) and Duncan’s Multiple Range Test (DMRT) were performed using the StatGraphics CENTURIONÒ XV 2005 software and Uniwin PLUSÒ 2005 v6.1.
We wanted to highlight the nutritional profile and potential uses of fruits and vegetables from Martinique. We compared them with commonly consumed temperate plants known for their nutritional potential. Analysis of the results is summarized in
The total carotenoid content of fruits and vegetables was also analyzed. The comparison of tropical (colored) and temperate (black) vegetables’ total carotenoid content (µg/100g) is represented in
Scientific Names | Fruits | Total Polyphenols (mg/100g) | Total Carotenoids (µg/100g) | Vitamin C (mg/100g) |
---|---|---|---|---|
Anacardium occidentale | Cashew apple | 603 ± 14 | 924 ± 31 | 555.8 ± 22.3 |
Ananas comosus | Pineapple | 73.3 ± 5.3 | 497 ± 17 | 38.3 ± 1.0 |
Annona muricata | Soursop | 183.4 ± 56.7 | 0 | 16.3 ± 0.3 |
Annona squamosa | Custard apple | 388.3 ± 7.7 | 0 | 11.5 ± 0.1 |
Artocarpus heterophyllus | Jackfruit | 101.7 ± 2.1 | 131.7 ± 12.3 | 13.6 ± 1.3 |
Averrhoa carambola | Star fruit | 366.3 ± 7.3 | 112 ± 19 | 14.2 ± 0.3 |
Carica papaya | Raw papaya | 43.5 ± 2.4 | 113 ± 11 | 39.3 ± 0.3 |
Carica papaya | Cooked papaya | 38.6 ± 4.8 | 83.3 ± 3.1 | 25.7 ± 0.3 |
Chrysophyllum cainito | Star apple | 515 ± 21 | 26.3 ± 1.5 | 5.6 ± 1.8 |
Citrullus lanatus | Watermelon | 22.8 ± 4.2 | 541.7 ± 39.1 | 7.9 ± 0.2 |
Citrus aurantifolia | Giant key lime | 213.2 ± 20.7 | 63.8 ± 76.3 | 23.7 ± 0.3 |
Citrus aurantifolia | Lemon | 111.7 ± 9.7 | 446.8 ± 247.4 | 23.2 ± 0.9 |
Citrus aurentium | Bitter orange | 350 ± 74 | 575.2 ± 141.7 | 44.5 ± 0.8 |
Citrus latifolia | Lima citrus | 31.7 ± 2.7 | 310.3 ± 24.6 | 18.5 ± 0.3 |
Citrus maxima | Shaddock | 112.7 ± 9.7 | 909.8 ± 381.9 | 44.2 ± 2.5 |
Citrus maxima | Grapefruit | 59.2 ± 2.3 | 448.4 ± 248.1 | 35.6 ± 1.2 |
Citrus reticulata | Common mandarin | 102.2 ± 1.4 | 714.7 ± 4.1 | 26.7 ± 0.6 |
Citrus reticulata | Macaque mandarin | 76.2 ± 0.3 | 2136.7 ± 16.2 | 6.1 ± 0.0 |
Citrus sinensis | Orange | 131.8 ± 11.9 | 331.6 ± 195.8 | 41.2 ± 0.7 |
Citrus spp, | Sour orange | 83.5 ± 4.3 | 525.3 ± 59.6 | 29.9 ± 0.9 |
Cucumis melo | Melon | 42.4 ± 2.4 | 535.7 ± 46.1 | 27.2 ± 0.3 |
Lycopersicum esculentum | Tomato | 42 ± 1.3 | 660 ± 29 | 15.2 ± 0.2 |
Malpighia punicifolia | Acerola | 727.4 ± 200.4 | 422.3 ± 10.3 | 2853.8 ± 10.6 |
Mammea americana | Mamey apple | 117.1 ± 0.3 | 3199.7 ± 12.4 | 2.7 ± 0.0 |
Mangifera indica | Bassignac mango | 95.58 ± 6.11 | 2183.00 ± 642.05 | 16.0 ± 11.3 |
Mangifera indica | Moussache mango | 57.0 ± 20.0 | 449.33 ± 633.11 | 30.85 ± 1.06 |
Mangifera indica | Green mango | 86.40 ± 14.91 | 276.17 ± 388.67 | 28.20 ± 0.85 |
Mangifera indica | Julie mango | 117.50 ± 7.37 | 954.00 ± 52.33 | 34.50 ± 13.44 |
Passiflora edulis | Passion fruit | 50.4 ± 1.4 | 339 ± 46 | 54.3 ± 2.3 |
Passiflora laurifolia | Water melon | 44 ± 9 | 11 ± 2 | 41.4 ± 0.3 |
Psidium guajava | Guava | 422.7 ± 25.6 | 604.3 ± 12.1 | 491.6 ± 1.7 |
Punica granatum | Pomegranate | 189.6 ± 35.9 | 9.7 ± 1.1 | 19.8 ± 1.0 |
Spondias cythera Sonnerat | Ripe golden apple | 157 ± 13 | 752.7 ± 14.3 | 20.1 ± 0.2 |
Spondias cythera Sonnerat | Green golden apple | 158 ± 5 | 836.3 ± 9.3 | 23.9 ± 0.4 |
Spondias mombin | Hog plum | 250.9 ± 8.3 | 821 ± 22 | 10.1 ± 0.1 |
Syzygium malaccense | Malay apple | 301 ± 23 | 0 | 0.3 ± 0.1 |
Data are expressed per 100 g of fresh edible material. An asterix indicates fruits treated in juice for analyses.
Scientific Names | Vegetables | Total Polyphenols (mg/100g) | Total Carotenoids (µg/100g) | Vitamin C (mg/100g) |
---|---|---|---|---|
Abelmoschus esculentus | Okra | 224.9 ± 25.3 | 552.3 ± 35.2 | 2.9 ± 0.0 |
Artocarpus altilis | Breadfruit | 29.4 ± 0.2 | 245.0 ± 20.6 | 8.2 ± 0.1 |
Cajanus cajan | Pigeonpea | 978.6 ± 34.8 | 364.3 ± 9.3 | 569.2 ± 41.1 |
Calathea allouia | Jerusalem artichoke | 29.8 ± 4.4 | 136.3 ± 7.6 | 9.7 ± 0.4 |
Colocasia esculenta | Dasheen | 87.0 ± 8.5 | 51.3 ± 1.5 | 4.1 ± 0.1 |
Cucumis anguria | Bur cucumber | 49.4 ± 7.7 | 16.7 ± 3.2 | 73.2 ± 1.2 |
Cucumis sativus* | Cucumber | 11.7 ± 4.5 | 52.0 ± 1.9 | 0.3 ± 0.0 |
Cucurbita moschata | Local pumpkin | 27.03 ± 1.86 | 9269.7 ± 25.6 | 0.1 ± 0.0 |
Cucurbita moschata | Phoenix pumpkin | 31.5 ± 0.1 | 7714.7 ± 20.7 | 0.1 ± 0.0 |
Dioscorea alata | St. Marteen yam | 214.1 ± 5.1 | 86.3 ± 1.5 | 22.0 ± 0.6 |
Dioscorea cayenensis-rotunda | Yellow yam | 30.5 ± 1.4 | 444.1 ± 0.1 | 8.5 ± 0.1 |
Dioscorea trifida | Couscoushe yam | 55.9 ± 2.4 | 73.3 ± 4.2 | 0.87 ± 0.05 |
Ipomoea batatas | Sweet potato | 30.8 ± 2.2 | 2443.3 ± 25.2 | 12.5 ± 0.5 |
Manihot esculenta | Sweet cassava | 23.9 ± 1.4 | 0 | 21.3 ± 0.7 |
Musa spp. | Plantain | 42.1 ± 0.1 | 862.0 ± 11.8 | 6.1 ± 0.1 |
Musa spp. | Green banana | 46.6 ± 1.4 | 247.7 ± 2.3 | 9.2 ± 0.1 |
Nasturtium officinale | Watercress | 90.6 ± 8.6 | 4339.0 ± 15.9 | 2.7 ± 0.5 |
Sechium edule | White Christophine | 47.2 ± 8.8 | 291.0 ± 7.5 | 7.4 ± 0.2 |
Sechium edule | Green Christophine | 41.2 ± 9.4 | 414.3 ± 23.4 | 12.5 ± 0.3 |
Xanthosoma sagittifolium | Malanga | 211.4 ± 29.0 | 355.7 ± 9.6 | 19.3 ± 1.2 |
Data are expressed per 100 g of fresh edible material. An asterix indicates raw vegetables for analyses.
Scientific Names | Fruits and Vegetables | Total Polyphenols (mg/100g) | Vitamin C (mg/100g) | Total Carotenoids (µg/100g) |
---|---|---|---|---|
Euterpe oleracea | Acai | 604.69 ± 0.00 | 58.72 ± 0.00 | 5.07 ± 0.00 |
Malus domestica | Apple | 179.1 ± 148.3 | - | - |
Prunus armeniaca | Apricot | 133.00 ± 0.00 | - | - |
Cynara scolymus | Artichoke | 321.3 ± 166.7 | - | - |
Rubus fruticosus | Blackberry | 569.43 ± 226.05 | 24.57 ± 9.15 | 0.27 ± 0.00 |
Ribes nigrum | Blackcurrant | 820.64 ± 230.06 | 179.50 ± 16.46 | 8 ± 0 |
Vaccinium corymbosum | Blueberries | 525 ± 0 | 16.97 ± 10.09 | 30 ± 0 |
Brassica oleracea | Broccoli | 98.9 ± 13.5 | - | - |
Brassica oleracea | Brussels Sprout | 220.75 ± 183.49 | - | - |
Vaccinium macrocarpon | Cranberry | 198 ± 101 | 11.60 ± 1.42 | 200 ± 0 |
Vitis vinifera | Grapes | 153.39 ± 49.86 | 6.24 ± 3.34 | 30 ± 0 |
Actinidia deliciosa | Kiwi | 315 ± 0 | 78.33 ± 17.15 | 50 ± 0 |
Morinda citrifolia | Noni | 91.9 ± 0.0 | 53.2 ± 0.0 | 3.5 ± 0.0 |
Hylocereus undatus | Pitahaya | - | 29 ± 0 | - |
Solanum tuberosum | Potato | 53.86 ± 34.87 | 13.50 ± 4.95 | 5.2 ± 0.0 |
Rubus idaeus | Raspberry | 148.10 ± 93.55 | 26.20 ± 2.67 | 30 ± 0 |
Allium cepa | Shallot | - | - | - |
Fragaria virginiana | Strawberry | 289.20 ± 95.22 | 64.81 ± 13.20 | 20 ± 0 |
Data presented here represent averages from worldwide food composition tables or values found in literature [
tively. Their Vitamin C content was also higher than blackcurrant (more than 3 times higher) and kiwi (more than 9 times higher). Lower down on the scale, pineapple, papaya, passion fruit, and guava covered more than 70% of RDI, with levels of between 54.3 and 38.3 mg/100g.
Total carotenoid content (µg/100g) is represented in
Data from the processing of some of the fruits and vegetables from Martinique was established. Two fruits and four vegetables were specifically studied here: mamey, mandarin, pumpkin, okra, sweet potato and christophine. Results are summarized in
mg respectively. Sweet potatoes were rich in total polyphenols (373.84 mg) and carotenoids (3.84 mg), and were a source of Vitamin C (16.00 mg). Sweet potato flour was very rich in carotenoids (3.43 mg) and total polyphenols (587.77 mg). Okra was rich in total polyphenols, with 1800.90 mg. Its total polyphenol content was 19 times richer than broccoli.
The total polyphenol content was statistically the highest (5%) in the raw material for all fruits and vegetables, except for pumpkin, where it was higher in the fresh-cut packaged product. Heat treatments had a statistically significant effect (5%) on total polyphenol content. The processes of pasteurization, sterilization (canning) and vacuum frying (chips) were in the lowest statistical groups. Steaming had the least impact on total polyphenols. Cooking methods had a statistically significant effect (5%) on total polyphenol content. The more fruits and vegetables were heated, the more their polyphenol content decreased.
For products made from mamey apples, a significant loss of total polyphenols between the raw material and processed products was observed. The loss was statistically higher in chips. There was a 42% loss of total polyphenols in canned products and 76% in chips compared to the raw material. During the preparation of peach sy-
Plant | Product/Process | Total Polyphenols (mg) | Total Carotenoids (mg) | Vitamin C (mg) |
---|---|---|---|---|
Mamey | crushed raw (raw material) | 804.17 ± 7.27 a | 21.97 ± 0.31 a | 18.60 ± 0.21 a |
canned | 463.88 ± 2.60 b | 9.95 ± 0.14 b | 0.00 ± 0.00 b | |
crisps | 194.77 ± 2.15 c | 6.55 ± 0.16 c | 0.20 ± 0.00 b | |
p | 0.0000 | 0.0000 | 0.0000 | |
Pumpkin | steamed crushed (raw material) | 333.23 ± 14.26 c | 97.79 ± 17.23 a | - |
fresh-cut packaged | 467.89 ± 45.95 a | 79.44 ± 12.24 b | ||
frozen | 406.25 ± 18.17 b | 64.29 ± 3.93 c | ||
crisps | 380.71 ± 72.49 bc | 29.61 ± 1.06 d | ||
p | 0.0004 | 0.0000 | ||
Mandarin | pure filtered juice (raw material) | 1022.11 ± 15.20 a | 7.15 ± 0.16 a | 266.79 ± 10.29 a |
pure filtered pasteurized juice | 851.33 ± 57.24 b | 7.55 ± 0.46 a | 248.17 ± 19.47 a | |
canned | 469.88 ± 76.13 c | 5.48 ± 0.82 b | 1.25 ± 0.17 b | |
p | 0.0001 | 0.0081 | 0.0000 | |
Okra | steamed crushed (raw material) | 1800.90 ± 209.16 a | 4.43 ± 0.33 b | - |
frozen | 1341.23 ± 18.74 b | 10.36 ± 0.96 a | ||
canned | 1049.45 ± 63.60 c | 1.55 ± 0.13 c | ||
p | 0.0010 | 0.0000 | ||
Sweet potato | steamed crushed (raw material) | 373.84 ± 7.36 b | 3.84 ± 0.14 b | 16.00 ± 0.07 a |
frozen | 340.27 ± 8.10 b | 6.22 ± 0.08 a | 10.83 ± 0.12 b | |
flour | 587.77 ± 29.25 a | 3.43 ± 0.06 c | 0.00 ± 0.00 c | |
p | 0.0000 | 0.0000 | 0.0000 | |
Christophine (white) | steamed crushed (raw material) | 278.23 ± 28.52 a | - | 77.43 ± 3.86 a |
frozen | 285.11 ± 55.61 a | 72.81 ± 5.66 a | ||
canned | 249.73 ± 17.71 a | 3.42 ± 0.85 b | ||
p | 0.5565 | 0.0000 |
rup, Asami et al. [
For mandarins, there was a difference of 53% between the polyphenol content of the pure fresh juice and pure pasteurized juice. For canned fruit, the gap between fresh and processed widens to 86%. Jiratanan and Liu [
In the case of christophine and okra, the total polyphenol content was significantly (5%) the highest in raw and frozen material, whilst canned products were in the lowest statistical group.
Statistically, sweet potato flour had the lowest polyphenol content. It was almost 3.5 times lower than for steamed sweet potatoes. After drying for 24 hours at 60˚C, Yang and Gadi [
There was a significant loss of carotenoids following food processing of mamey apples. The highest loss was for chips. Nevertheless, chips still had a carotenoid content 100 times greater than that of potato chips [
For pumpkin, primary raw material (cooked/crushed) had the statistically higher carotenoid content (compared with dry matter). Chips had a significantly lower carotenoid content. Frozen pumpkin cubes were in third position behind fresh-cut packaged.
Total carotenoid content of mandarin products was significantly higher in pure juice. Canned mandarin had the lowest content. In a study on total carotenoid composition of cashew apple juice, both fresh and pasteurized, Cecchi and Rodriguez-Amaya [
Carotenoid content was statistically higher in frozen okra and in raw material (cooked and crushed). Canned okra was in the lowest statistical group. There was a difference of +57% in frozen compared to raw material and a difference of +85% between frozen and canned.
Total carotenoid content of frozen sweet potatoes was statistically the highest. It was more than 1.5 times higher than the crushed cooked sweet potato (raw material). Carotenoid content measured by Reddy and Sistrunk [
A significant loss (5%) of the total Vitamin C between raw material and processed products in mamey apples was observed. There was no significant difference between canned and chips.
There was no significant difference between pure filtered mandarin juice and the pasteurized juice. There was lower loss of Vitamin C in orange juices following conventional treatment (9%), but much less when lower temperatures were applied [
Vitamin C content of steamed sweet potatoes (raw material) was statistically the highest, followed by blanched frozen sweet potatoes. Amiot-Carlin et al. [
Sweet potato flour was in the lowest statistical group with a total loss of Vitamin C. Vitamin C was sensitive to air drying. For peppers, the result of drying was an 88% loss of Vitamin C [
There was no significant difference (5%) in the Vitamin C content of steamed and blanched frozen christophine (raw material). Vitamin C content was significantly lowest in canned. Blanched frozen christophines were 1.5 times richer in Vitamin C than global values for zucchini and frozen green beans.
This study highlights the nutritional profile and potential uses of fruits and vegetables from Martinique. Overall, fruit and vegetable from Martinique were richer than temperate fruits and vegetables in polyphenols, Vitamin C and total carotenoids. The antioxidant potential of tropical fruits and vegetables is little studied to date, and this first study demonstrates the richness of these plants, often not consumed. Lim et al. [
In general, processing treatments had an effect on various nutrient contents in plants from Martinique. Heat treatment and cooking had a statistically significant effect. Boiling caused the diffusion of total polyphenols, while steaming had less impact. There was a statistically significant effect of vacuum frying on total carotenoid content. This loss was due to the distribution of carotenoids, which are soluble compounds, in the cooking oil. Total carotenoids were sensitive to oxidation and, to a lesser extent, sterilization. There was a statistically significant effect (5%) on Vitamin C content from sterilization, vacuum frying, drying and steaming. This effect was even more pronounced the higher the temperature and the longer the processing time. There is higher nutritional value in consuming a portion of fresh mamey because of its Vitamin C and antioxidant content. Although chips concentrated nutrients (carotenoids and total polyphenols) compared to raw material, their consumption provided fat and carbohydrates. A portion of mamey chips provides twice the level of carotenoids, 1.5 times the total polyphenols and twice as much fibre compared to the fresh fruit, but five times the carbohydrates and more than 100 times the fat. Pumpkin is of high nutritional value with a high carotenoid content. It is better to consume a steamed pumpkin portion for its carotenoid content whilst fresh-cut packaged is of value for the total polyphenol content. As for fresh mamey, we found that processing into chips concentrated nutrients (total polyphenols and carotenoids) but added fat. Pasteurization had little impact on nutritional and functional quality of mandarins. However, filtration of juice leads to the retention of several nutrients. Finally, sterilization resulted in a significant loss of vitamins. From a nutritional standpoint, it is better to consume pure mandarin juice for its Vitamin C and polyphenol contents. Steamed or frozen Okra (subsequently steamed) were very rich in total carotenoids and total polyphenols. Consumption in these forms offers a higher nutritional profile than consumption of the canned vegetable. Steamed sweet potato from Martinique was rich in carotenoids and polyphenols and a source of Vitamin C. Consumption of steamed or frozen (subsequently blanched) offers a higher nutritional profile than its consumption as sweet potato flour. Similarly, consumption of christophine after steaming offers more nutrients than its frozen or canned form. It was rich in antioxidants and a source of Vitamin C.
Cooking methods statistically decreased total polyphenol contents. Polyphenols are hydrosoluble and losses observed during blanching/freezing and sterilization processes are due to diffusion of these nutrients in blanching water and in cooking juices. Anthocyanin content decreased as blanching time increased [
Tropical plants studied here had high nutritional and functional potential, especially in terms of antioxidant (polyphenols, carotenoids) and vitamin (nutrition) levels. The results showed that these values are equivalent to or even much higher than the levels found in commonly-consumed temperate plants known for their nutritional qualities. Fruits and vegetables from Martinique had a significant advantage in terms of their antioxidant capacity.
In conclusion, in order to get the most nutritional and functional value from tropical fruits and vegetables, it is recommended to consume them in fresh form for fruits, whilst vegetables should be eaten raw or cooked lightly using a method such as steaming. Boiling causes the diffusion of minerals and total polyphenols. Vacuum frying promotes a loss of total carotenoids and adds much more fat to the end product. Finally, cooking for longer times and at high temperatures, which is the case for sterilization (canning), causes a sharp decrease in vitamin content. Overall, this study shows that fruits and vegetables grown in Martinique provide numerous health benefits for humans.
We would like to thank the Regional Council of Martinique (F.W.I.) and the FEDER for its financial support. Special thanks also go to producers who provided fruits and vegetables for the study. Ms. Annie Batten is also greatly thanks for her help in English proof reading.