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1.
Vitamin A deficiency is a disorder of public health importance in Sri Lanka. A recent national survey revealed that 36% of preschool children in Sri Lanka have vitamin A deficiency (serum retinol <0.2 µg ml?1). In view of its well‐established association with child morbidity and mortality, this is a reason for concern. One of the main fruits which has been recommended for prevention of vitamin A deficiency in Sri Lanka is papaya (Carica papaya L). In this study the carotenoid profiles of yellow‐ and red‐fleshed papaya were analysed by medium‐pressure liquid chromatography (MPLC) and UV‐vis spectrophotometry. A section of yellow‐fleshed papaya showed small carotenoid globules dispersed all over the cell, whereas in red‐fleshed papaya the carotenoids were accumulated in one large globule. The major carotenoids of yellow‐fleshed papaya were the provitamin A carotenoids β‐carotene (1.4 ± 0.4 µg g?1 dry weight (DW)) and β‐cryptoxanthin (15.4 ± 3.3 µg g?1 DW) and the non‐provitamin A carotenoid ζ‐carotene (15.1 ± 3.4 µg g?1 DW), corresponding theoretically to 1516 ± 342 µg kg?1 DW mean retinol equivalent (RE). Red‐fleshed papaya contained the provitamin A carotenoids β‐carotene (7.0 ± 0.7 µg g?1 DW), β‐cryptoxanthin (16.9 ± 2.9 µg g?1 DW) and β‐carotene‐5,6‐epoxide (2.9 ± 0.6 µg g?1 DW), and the non‐provitamin A carotenoids lycopene (11.5 ± 1.8 µg g?1 DW) and ζ‐carotene (9.9 ± 1.1 µg g?1 DW), corresponding theoretically to 2815 ± 305 µg kg?1 DW mean RE. Thus the carotenoid profile and organisation of carotenoids in the cell differ in the two varieties of papaya. This study demonstrates that carotenoids can be successfully separated, identified and quantified using the novel technique of MPLC. Copyright © 2003 Society of Chemical Industry  相似文献   

2.
Acerola is now commercially produced and processed in Brazil. Known for its very high vitamin C content, this fruit is also a good source of β‐carotene. The present study was carried out to verify variation in the carotenoid composition along the food chain. Neoxanthin, violaxanthin, lutein, β‐cryptoxanthin, α‐carotene and β‐carotene were found in the acerola fruit. β‐Carotene predominated with mean concentrations of 12.4 and 38.1 µg g?1 in the ripe fruit, 8.8 and 30.1 µg g?1 in the peeled ripe fruit and 5.4 and 12.0 µg g?1 in the partially ripe fruit of an undefined variety taken from home gardens and the commercial cultivar Olivier, respectively. Aside from β‐carotene, β‐cryptoxanthin increased significantly in both garden and commercial fruits and violaxanthin in the latter fruits during ripening. Peeling reduced β‐carotene in both garden and commercial lots, violaxanthin decreased in the commercial fruits, and the other carotenoids remained virtually unchanged. Four brands of frozen pulp and three brands of processed juice had variable and markedly lower carotenoid levels than those of the fresh fruit, indicating that the processing should be improved. Copyright © 2006 Society of Chemical Industry  相似文献   

3.
Effects of high‐pressure treatment on the orange juice carotenoids (β‐carotene, α‐carotene, zeaxanthin, lutein and β‐cryptoxanthin) associated with nutritional (vitamin A) and health‐related (radical‐scavenging capacity) values were investigated. Various high‐pressure treatments (50–350 MPa) combined with different temperatures (30 and 60 °C) and times (2.5, 5 and 15 min) of treatment were assayed. The carotenoid content of the orange juice was analysed by HPLC‐UV, the vitamin A value was determined as retinol equivalents (RE) and the free radical‐scavenging capacity was evaluated using the DPPH (2,2‐diphenyl‐1,1‐picrylhydrazyl) radical model system. A storage study was carried out at refrigeration temperature (4 °C). High‐pressure treatments at 350 MPa produced significant increases of 20–43% in the carotenoid content of fresh orange juice (from 3.99 to 4.78–5.70 mg l?1). A non‐uniform behaviour of high‐pressure treatments was detected. An increase in time (beyond 5 min) or temperature (above 30 °C) of treatment did not improve the amount of carotenoids extracted. Owing to better extraction of carotenoids, an increase in vitamin A value from 164 to 238 RE l?1 (45%) was achieved with the 350 MPa/30 °C/5 min treatment. No correlation was found between the increase in carotenoid amount extracted and the free radical‐scavenging activity. © 2002 Society of Chemical Industry  相似文献   

4.
BACKGROUND: Chitosan can form antimicrobial, semi‐permeable barriers that limit gas exchange and reduces water loss in fruits. Consumer interest in fresh‐cut papaya fruit is leading to increasing demand because of its sensorial and antioxidant properties. However, papaya is a highly perishable product that is prone to loss of weight, loss of firmness and microbial attack. The aim of this study was to evaluate the effect of chitosan coatings on the overall quality of fresh‐cut papaya. Chitosan coatings of low (LMWC), medium (MMWC) and high (HMWC) molecular weights, at concentrations of 0.01 and 0.02 g mL?1, were applied to fresh‐cut papaya cubes. The treated cubes were stored at 5 °C and changes in quality were evaluated. RESULTS: MMWC maintained the highest color values (L* and b*) and firmness. Chitosan coatings suppressed mesophilic plate count, and the growth of molds and yeast, compared to controls. The MMWC coatings at 0.02 g mL?1 resulted in the highest antimicrobial activity and decreased the activity of the enzymes polygalacturonase and pectin methylesterase, followed by low and high MW chitosan coatings at 0.02 g mL?1. CONCLUSION: The application of the MMWC treatment at 0.02 g mL?1 could be used to reduce deteriorative processes, maintain quality and increase the shelf life of fresh‐cut papaya stored at 5 °C. Copyright © 2008 Society of Chemical Industry  相似文献   

5.
Commercial tomato canning yields two different byproducts. One is the material that results from peeling tomatoes, while the other results from removing the seeds. The peel byproduct contained 100.8 g protein, 256.4 g ash and 299.4 g acid detergent fiber kg?1. Ash content was high because the peel byproduct contained 83.8 g kg?1 sodium as a result of using a sodium hydroxide solution to peel the tomatoes. The seed byproduct contained 202.3 g protein, 51.8 g ash, and 537.9 g acid detergent fiber kg?1. An amino acid analysis of seeds indicated that approximately 60% of the protein results from amino acids. Both byproducts were analyzed for carotenoid content. The lycopene content of peel byproduct was 734 µg g?1 of dry material. Significant amounts of lutein, β‐carotene, and cis‐β‐carotene were also present. Seed byproduct contained 130 µg lycopene kg?1 of dry matter. The content of other carotenoids was approximately half of that present in the peels. Peel and seed byproducts were included at 75 g kg?1 in hen diets to determine the transfer of carotenoids to the yolk. When fed at this concentration, the lycopene content of dry egg yolk was approximately 0.9 µg g?1. Approximately 0.1% of the lycopene in peel byproduct and approximately 0.7% of the lycopene in the seed byproduct was transferred from the feed to the yolk. Lycopene appears more similar to carotene than to oxycarotenoids in its transfer to the yolk. Copyright © 2005 Society of Chemical Industry  相似文献   

6.
: The effect of cutting shape (cubes or slices) and storage temperature (5 °C, 10 °C, and 20 °C) on overall quality of fresh‐cut papaya were investigated. CO2 production, color, firmness, total soluble solids (TSS), weight loss, overall quality, ascorbic acid, β‐carotene, and antioxidant capacity were evaluated as a function of shelf life. CO2 production was high on day 0 for cubes and slices with an average of 150 and 100 mL/ kg/h, respectively. Storage temperature did not affect color changes; however, lower temperatures prevented loss of firmness. Fresh‐cut papaya stored at 20 °C showed the lowest TSS value and the highest weight losses. Shelf life based on visual quality ended before significant losses of total ascorbic acid, b‐carotene, and antioxidant capacity occurred. In general, quality parameters were not affected by shape. However, slices stored at 10 °C and 5 °C had a shelf life of 1 d and 2 d longer than cubes, respectively.  相似文献   

7.
BACKGROUND: The process of convective drying was evaluated in terms of the bioactive compounds contained in nopal samples before and after dehydration. Total polyphenol, flavonoid, flavonol, carotene and ascorbic acid contents were determined in undehydrated and dehydrated samples. Two drying temperatures (45 and 65 °C) and two air flow rates (3 and 5 m s?1) were evaluated. The rheology of samples under the best drying conditions was also studied, since it provides important information regarding processing (mixing, flow processing) as well as the sensory attributes (texture) of rehydrated samples. RESULTS: Non‐Newtonian shear‐thinning behaviour was observed for samples dried at 45 °C, while samples dried at 65 °C showed shear‐thickening behaviour, possibly caused by thermal chain scission of high‐molecular‐weight components. CONCLUSION: The best conditions for bioactive compound preservation were a drying temperature of 45 °C and an air flow rate of 3 m s?1, resulting in 40.97 g phenols, 23.41 g flavonoids, 0.543 g β‐carotene and 0.2815 g ascorbic acid kg?1 sample as shown in table 3. Copyright © 2011 Society of Chemical Industry  相似文献   

8.
Tomato products (pulp, puree and paste) submitted to accelerated aging (30, 40 and 50 °C for 3 months) were studied to evaluate variations in the kinetics of the degradation of antioxidants and antioxidant activity. The carotenoids lycopene and β‐carotene, ascorbic acid, rutin and total phenolics were analysed. The antioxidant activity was measured using (a) the xanthine oxidase (XOD)/xanthine system, which generates superoxide radicals and hydrogen peroxide, and (b) the linoleic acid/CuSO4 system, which promotes lipid peroxidation. The ascorbic acid content decreased even at 30 °C, following pseudo‐first‐order kinetics, with an activation energy of 105 200 J mol?1 for tomato pulp and 23 600 J mol?1 for tomato paste. The lower the initial ascorbic acid content, the higher was the degradation rate. Variations in phenolic compounds occurred at 40 °C and higher, following pseudo‐zero order kinetics. The antioxidant activity of the hydrophilic fraction of the tomato products depended on both antioxidant degradation and the Maillard reaction and could not be described by a kinetic model. The β‐carotene content decreased even at 30 °C, whereas the lycopene content was stable in all samples. The antioxidant activity of the lipophilic fraction of the tomato products decreased following pseudo‐first order kinetics, with an activation energy of 22 200 J mol?1 for tomato pulp and 20 200 J mol?1 for tomato paste. It is concluded that significant ‘oxidative damage’ can occur in tomato products during their commercial shelf‐life. Copyright © 2003 Society of Chemical Industry  相似文献   

9.
Effect of Gaseous Ozone on Papaya Anthracnose   总被引:1,自引:0,他引:1  
Anthracnose caused by the fungus Colletotrichum gloeosporioides is considered as one of the most devastating postharvest disease of papaya. The aim of this study was to evaluate the effectiveness of gaseous ozone as a potential antifungal preservation technique to overcome anthracnose disease of papaya during cold storage. Different concentrations of ozone (0 (control), 0.04, 1.6, and 4 ppm) were applied for various exposure durations (48, 96, and 144 h). Radial mycelia growth and conidial germination were evaluated in vitro after fungal exposure to the different levels and durations of ozone. Significant inhibition in radial mycelia growth of C. gloeosporioides was observed (p?<?0.05) in all ozone treatments as compared to the control during 8 days of incubation at room temperature (25?±?3 °C). Ozone treatment of papaya fruit with 1.6-ppm ozone for 96 h delayed and simultaneously decreased the disease incidence to 40 % whereas disease severity was rated at 1.7, following 28 days of storage at 12?±?1 °C and 80 % relative humidity. The scanning electron microscopy showed that 4-ppm ozone caused disintegration of spore structure and did not affect the cuticular surface of fruit. Thus, ozone fumigation can reduce postharvest losses of papaya caused by anthracnose.  相似文献   

10.
The effects of organic farming, pasteurisation and addition of β‐cyclodextrin on the content of vitamin C, colour, carotenoids and antioxidant capacity of orange juices were studied. After pasteurisation at 98 °C (20 s) and subsequently storage along 145 days at room temperature (20–25 °C), the loss of vitamin C content was around 30%. The effects of the thermal process on carotenoid were clearly observed in lutein (loss of 16% for organic and traditional 8%) and especially β‐cryptoxanthin (loss of 30%). The colour changes were noticeable after the pasteurisation of orange juice and subsequent storage, with significant decreases being observed in lightness and the coordinate a*, while increases were found for coordinates b*, Hue* and chroma. The antioxidant capacity was 0.075 ± 0.01 and 0.053 ± 0.01 mMT mL?1 for organic and conventional, respectively, with losses around 40% being found at the end of the storage period. The addition of β‐cyclodextrin caused no significant effects on the parameters under analysis. These data showed that strong thermal treatments, such as pasteurisation, adversely affect the nutritional and sensory quality of orange juices.  相似文献   

11.
BACKGROUND: This study was conducted to determine the chemical and microbial stability of high moisture (HM) dried apricots during storage at 5, 20 and 30 °C for a period of 8 months. HM dried apricots were obtained by rehydrating dried apricots in ‘water’ and ‘water + H2O2’. RESULTS: Analysis of kinetic data suggested first‐order models for loss of SO2 and non‐enzymatic browning reactions. Higher storage temperatures increased the rate of SO2 loss and formation of brown colour in HM dried apricots. Results from extensive colour measurements (non‐enzymatic browning, reflectance colour and β‐carotene) revealed that the colour of HM dried apricots stored at 5 °C was almost unchanged during 8 months of storage. The colour of samples stored at 30 °C was unacceptable starting from 2 months of storage. Total mesophilic aerobic bacteria counts decreased 0.7, 1.1 and 1.5 log cycles after 8 months of storage at 5, 20 and 30 °C, respectively. For the same storage period, the decrease in mesophilic bacteria was 0.62 log cycle in samples rehydrated in ‘water + H2O2’ and stored at 20 °C. CONCLUSION: These results suggest that HM dried apricots should be stored at temperatures lower than 20 °C to preserve the characteristic golden yellow colour. A relatively low level of SO2 (1458 mg kg?1 at 200 g kg?1 moisture level) was sufficient to prevent the growth of spoilage organisms in HM dried apricots at all three storage temperatures. Copyright © 2008 Society of Chemical Industry  相似文献   

12.
Recent studies have demonstrated that vitamin C, phenols, and carotenoids are bioactive compounds that protect the body from oxidative stress, reducing the risk of cardiovascular diseases and some types of cancer. Qualitative and quantitative analysis of the major phytochemicals found in papaya fruit flesh and skin (Carica papaya L., cv Maradol) was conducted in four stages of ripeness, using high-performance liquid chromatography mass spectrometry. Phenolic compounds identified in the fruit skin tended to decrease with ripening. The compounds identified were ferulic acid (277.49 to 186.63 mg/100 gDW), p-coumaric acid (229.59 to 135.64 mg/100 gDW), and caffeic acid (175.51 to 112.89 mg/100 gDW). The following carotenoids, along with vitamin C, increased in flesh with ripening; lycopene (0.36 to 3.40 mg/100 gDW), ??-criptoxanthin (0.28 to 1.06 mg/100 gDW), ??-carotene (0.23 to 0.50 mg/100 gDW), and vitamin C (25.07 to 58.59 mg/100 gDW). These results indicate that stage of ripeness significantly influences the contents of bioactive compounds in papaya fruit.  相似文献   

13.
Pectinesterase (PE) was partially purified from papaya pulp, and its biochemical properties were studied. The enzyme was eluted in a single peak after DEAE-cellulose and Sephadex G-100 chromatography. The PE had a molecular weight of 53000 and showed an optimum pH of 8.0. Its activity was dependent on an NaCl concentration of 0.2M . The enzyme was heat stable: approximately 80% of the original activity remained after 60 min of heating at 50°C but completely inactivated by incubation at 80°C for 1 min. The activity was linear with time and protein concentration. The maximum reaction in 3 min was found at 60°C and the initial rate increased 9-fold from 20 to 60°C. The estimated Km was 0.12g litre?1 with citrus pectin as the substrate. The kinetic study revealed that polygalactur-onic acid is a competitive inhibitor, and a Ki value of 0.07 g litre?1 was determined. On the basis of this study, papaya PE properties resembled those of pectinesterase from other sources.  相似文献   

14.
Rapid degradation of fresh‐cut papaya limits its marketability. Hydrothermal treatments in combination with a calcium dip, applied to whole fruit before slicing, and also the application of chitosan as a coating film, have been found to have very good results in maintaining the quality of fresh‐cut fruits. Based on these considerations, the aim of this study was to evaluate the effect of hydrothermal treatment (HT; 49 °C, 25 min) containing calcium chloride (Ca; 1%, w/v) followed by dipping in chitosan (Chit; 1%, w/v, 3 min) on the physical, chemical, and microbial qualities of papaya slices stored at 5 °C for 10 d. Pulp color, firmness, ascorbic acid, total phenolics, β‐carotene, and lycopene were evaluated every 2 d while the microbial quality (mesophilics, psychrophilics, molds, and yeasts) was evaluated every 5 d. Fruit treated with HT‐Ca and HT‐Ca + Chit showed better color and firmness retention than Control and Chit. Papaya slices treated with HT‐Ca + Chit had higher nutritional content and lower microbial growth at the end of storage. The application of the HT‐Ca + Chit could be used to reduce deterioration processes, maintaining physical, chemical, and microbial qualities and increasing the shelf life of fresh‐cut papaya stored at 5 °C.  相似文献   

15.
The effects of six different polyglycerol esters of fatty acids (PGEs) as nonionic emulsifiers on the physicochemical properties and stability of β‐carotene nanoparticles in oil‐in‐water dispersions produced by an emulsification/evaporation technique were examined. The β‐carotene particle size was measured by a laser diffraction technique, and the stability and retention of β‐carotene during various preparation steps and storage were determined by HPLC. In the prepared nanodispersions the β‐carotene particle size decreased with increasing degree of glycerol polymerisation and decreasing carbon number of the fatty acid group in the PGE. The particle size of β‐carotene in nanodispersions containing polyglycerol monooleate was generally larger than that in the presence of polyglycerol monolaurate. During storage at 4 °C, although the β‐carotene content in the nanodispersions showed a significant ( P < 0.05) decrease with increasing storage period, the size distribution of β‐carotene was almost unchanged in all prepared nanodispersions. In general, the mean diameter of β‐carotene nanoparticles ranged from 85 to 132 nm. In the light of their ability to physically stabilise β‐carotene particle formation, it is suggested that PGEs with a high degree of glycerol polymerisation may be useful in the preparation of β‐carotene nanodispersions. The best stabilisation was obtained using 10 g kg?1 decaglycerol monolaurate. Copyright © 2004 Society of Chemical Industry  相似文献   

16.
The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi‐arid region of eastern Morocco) was evaluated through analysis of their phenolic and carotenoid contents. The composition of the phenolic compounds of safflower oil has not yet been documented. Therefore, in this preliminary study, Thirty different phenolic compounds were identified, and significant differences between the oil varieties were observed (P < 0.05). In the seed oil from the Rancho and Sharda safflower varieties, the main phenolic compound was trans‐chalcone, representing 13.45% and 11.8%, respectively, of the total phenolics, whereas in Cartamar and Cartafri oils, naringin accounted for 26.82% and 16.5%, respectively, of the total phenolics. The total carotenoid contents ranged from 1.13 mg kg?1 (Rancho) to 1.34 mg kg?1 (Cartamar and Cartafri). We observed that β‐cryptoxanthin (0.31–0.37 mg kg?1) and β‐carotene (0.3–0.35 mg kg?1) were the predominant carotenoids in all of the safflower oils that were studied.  相似文献   

17.
BACKGROUND: New varieties of fruits and vegetables, with higher carotenoid levels, are being developed to improve the potential health benefits to consumers. To assist the development of a new variety of high zeaxanthin sweetcorn, an analytical screening method was developed, including chromameter measurement of hue angle and optimized extraction for HPLC, and applied to 385 lines of a breeding population and six commercial varieties. RESULTS: Saponification had no effect on carotenoid extraction. In the breeding population, carotenoid levels had a wide range with the highest levels of zeaxanthin being 11.9 mg kg?1 fresh weight, which was at least six times greater than the tested commercial varieties. The regression of hue angle versus zeaxanthin was described by the equation, hue angle = 76.16 + 4.50 × exp(?0.24 × zeaxanthin) + 11.73 × exp(?0.24 × zeaxanthin), r2 of 0.59. The top 6% of lines, with regards to zeaxanthin (zeaxanthin + β‐cryptoxanthin + β‐carotene) and total carotenoids, all had hue angles ≤84.1°. CONCLUSION: The use of a hue angle of 85° as a maximum cut‐off for liquid extraction will allow for much increased efficiency in screening further germplasm for high zeaxanthin lines. There appears to be significant opportunity to further increase the zeaxanthin concentration by selecting for lines which preferentially channel carotenoid synthesis towards zeaxanthin. Copyright © 2009 Society of Chemical Industry  相似文献   

18.
Nectars are formulated beverages with a fruit juice or pulp as its main component. A blend of fruits can also be used, with the advantage of combining sensory and nutritional properties of different fruits. The beverages may be added with some energetic component, as caffeine, known by its stimulating effect on central nervous system. The objective of this study was to develop mixed nectar of cashew apple, papaya, guava, acerola fruit and passion fruit added caffeine. The beverage was prepared with 35% juice blend and 10% sugar, added with 100 mg of caffeine L?1 and 60 mg of sodium metabisulfite (SO2) L?1 and 500 mg of sodium benzoate L?1 as preservatives, packed in cleaned pasteurised bottles and heat processed at 90 °C for 30 s. Physicochemical, microbiological and sensory analyses of the beverage were performed initially (time zero) and during 6 months of storage at room temperature (about 25 °C). The products were microbiologically stable during storage. The vitamin C content decreased significantly throughout storage time, although it has remained relatively high. The product presented good sensory acceptance, which suggests its potential for market.  相似文献   

19.
Carotenoids in edible portions of plants can provide health benefits to humans. How growing conditions affect levels of carotenoids in pepper fruits as they mature is not well known. Five cvs of bell pepper (Bell Captain, Melody, North Star, Ranger, Red Beauty) and five cvs of pungent‐type peppers (Anaheim, Ancho, Cayenne, Pimento, Red Cherry) were grown in a glasshouse and in the field. Fruits were harvested at the green, turning (50% green) and mature red stages and analysed for levels of the carotenoids β‐cryptoxanthin, α‐carotene, β‐carotene, capsanthin, lutein and zeaxanthin and totals of these carotenoids. Levels of provitamin A: retinol equivalents (RE) were derived from levels of β‐cryptoxanthin, α‐carotene and β‐carotene. Levels of most carotenoids and RE were significantly higher in glasshouse‐grown plants, and most were higher in fruits at the red stage. Fruits of Ancho type had the most β‐cryptoxanthin, α‐carotene, β‐carotene, total carotenoids and RE, while fruits of Red Cherry type had the most capsanthin and zeaxanthin, and fruits of Bell Captain had the most lutein. Interactions of the main effects variables, ie location of production (field vs glasshouse), stage of development and cultivar, indicated differences in patterns of carotenoid levels and RE. The data indicated that growing conditions influenced carotenoid levels. The more consistent and protected conditions in the glasshouse may have caused carotenoid levels to be increased, especially at the red stage. Published in 2002 for SCI by John Wiley & Sons, Ltd  相似文献   

20.
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