Determination of free and bound carotenoids in paprika (Capsicum annuum L.) by LC/MS

Received: 17 August 1999     

In vitro bioaccessibility of carotenoids and tocopherols from fruits and vegetables

Aim of the study

To assess the in vitro bioaccessibility of carotenoids, including xanthophyll esters, and tocopherols from fruits and vegetables.

Results

Stability for carotenoids and tocopherols was over 70%. Xanthophyll esters were cleaved by cholesterol esterase but not by human pancreatic lipase. Less than 40% of the β-cryptoxanthin initially present was hydrolyzed and the amount of free xanthophylls recovered was higher when liquid was used than when fresh homogenized matrix was employed. cis-Isomers of β-carotene and lutein did not significantly increase during the process. Xanthophylls were more efficiently transferred into supernatants than tocopherols and β-carotene. cis-Carotenoids, epoxy-xanthophylls and ester forms were also transferred.

Conclusion

The results are consistent with observations in other in vitro digestion models and human studies and support the usefulness of in vitro assessment to study food-related determinants of the bioavailability of carotenoids and tocopherols from fruits and vegetables.     

Effects of supercritical CO2 fluid parameters on chemical composition and yield of carotenoids extracted from pumpkin

Pumpkin is a traditional food that is grown extensively worldwide and is believed to be beneficial to human health due to its high contents of carotenoids. The carotenoids in pumpkin were extracted by organic solvents and by supercritical carbon dioxide (SC-CO₂), and then they were identified, quantified, and compared. β-carotene (31 to 40 g per 100 g of total carotenoids) was the predominate carotenoid in pumpkin. Lutein and lycopene contents were much higher in SC-CO₂ extracts than those in organic solvent extract. Cis-β-carotene increased by more than two times in the SC-CO₂ extracts, even at a relatively low temperature of 40 °C, over those in the solvent extracts, indicating both enhanced solubility and isomerization from trans- to cis-β-carotene. The influences of modifier (10 mL/100 mL), temperature (40-70 °C), and pressure (25-35 MPa) of SC-CO₂ extraction on the change of carotenoid yields were also investigated. The highest yield (109.6 μg/g) was obtained at 70 °C and 35 MPa, with a 73.7% recovery. Selective extraction could be achieved by adjusting the temperature and pressure. Higher proportions of all-trans-β-carotene extracts were achieved at 40 °C under both 25 MPa and 35 MPa conditions. In order to extract more cis-isomers, a higher temperature of 70 °C was preferred.     

Effects of processing and storage on the stability of free and esterified carotenoids of red peppers (<Emphasis Type="Italic">Capsicum annuum</Emphasis> L.) and hot chilli peppers (<Emphasis Type="Italic">Capsicum frutescens</Emphasis> L.)

The stability of non-esterified carotenoids and carotenoid esters in paprika and chilli powder as affected by various processing treatments and storage conditions were studied. For this purpose, freshly harvested chilli and paprika pods were minced, immediately heated at 80, 90 and 100 °C for 5 and 10 min, respectively, and lyophilised. Alternatively, thermal treatment prior to mincing was applied. Processing resulted in a 25–34% loss of the initial carotenoid contents in chilli and 20–53% in paprika. Degradation of individual non-esterified carotenoids, mono- and diesters was monitored, generally showing an increased processing stability of mono- and diesters compared to their non-esterified counterparts. Capsanthin, capsorubin, zeaxanthin and β-cryptoxanthin mono- and diesters esterified with saturated fatty acids displayed similar stabilities, whereas susceptibility of the non-esterified pigments to degradation differed considerably. During storage over 4 months at ambient temperature pigment contents dropped by 16.7 and 9.6% in chilli and by 39.7 and 38.8% in paprika powders with and without illumination, respectively.     

Stability of carotenoids in tomato juice during processing

The stability of carotenoids in tomato juice as affected by various processing treatments was studied. Fresh tomatoes were crushed, hot-broken at 82 °C, screened and the juice was subjected to the following treatments: (1) heated at 90 °C for 5 min prior to canning; (2) heated in water at 100°C for 30 min after canning; (3) heated at 121°C for 40 s before canning (high-temperature-short-time treatment). The results showed that 16 carotenoids, including all-trans plus cis forms of lutein, lycopene and -carotene, were present in tomato juice. Most cis isomers of carotenoids showed inconsistent change during heating. The high-temperature-short-time treatment generated the highest yield of all-trans plus cis forms of lutein and lycopene, followed by heating at 90 °C for 5 min and heating in water at 100 °C for 30 min. Only a minor change in -carotene was observed for these heating treatments.     

Rehydration characteristics of freeze-dried tropical fruits

Rehydration behaviours of five freeze-dried fruits, namely, pineapple, mango, guava, acerola and papaya were investigated and related to the structural changes during drying and glass transition temperature. After freeze-drying performed under vacuum conditions (13 kPa) and initial sample temperature near to −30 °C, fruits were allowed to rehydrate at 25 °C in distilled water for 6 h. The Exponential, Peleg and Weibull equations were applied to fit the experimental data using non-linear regression analysis. The statistical criteria used to evaluate the goodness of fit of each equation were the coefficient of determination (R²), the standard error of estimate (SEE) and the mean relative percentage deviation modulus (MRD). The Weibull equation was found to be the most adequate for describing the rehydration kinetics, since it gave the higher R² values and lower SEE and MRD values for all fruits examined in this study. From indices that take into account the quantity of water absorbed and the losses of solutes, it was possible to fully characterize the rehydration process of the freeze-dried fruits. Their water uptake capacity was affected not only by injuries during moisture removal but also by structural collapse induced by the rehydration process itself, which was explained using the glass transition concept.     

Fatty acid composition of total lipids from some tropical storage organs

The fatty acids of the total lipid extracts made from 10 tropical storage organs (Alocasia macrorrhiza, Colocasia esculenta, Dioscorea alata, D. bulbifera, D. cayensis, D. rotundata, Ipomea batatas, etc.) were studied. The high occurrence of the C₁₈ unsaturated fatty acids (linoleate and linolenate which together contributed over 50 % on average of the total fatty acids), conferred a high level of unsaturation on almost species. Compared with similar storage organs of temperate regions, there was a definite reduction in the degree of unsaturation. This was brought about by a general increase in the intrinsic values of palmitate and oleate.     

Optimisation of growth parameters for the production of carotenoids by Rhodotorula gracilis

 Response surface methodological studies of growth parameters for carotenoid production by Rhodotorula gracilis (ATCC 90950) have been carried out for three parameters employed, namely glucose concentration (%), incubation period (days) and volume of inoculum (ml/100 ml). The results indicated maximum carotenogenesis (0.054%) at a 10% glucose level with a 2 ml/100 ml volume of inoculum for an incubation period of 9 days, which was also verified by experimental data. Received: 25 May 1998     

Cashew apple juice: its use in fortifying the nutritional quality of some tropical fruits

The physico-chemical properties of some tropical fruits (pineapple, orange, grape, mango and lemon) were analyzed and compared with those of cashew apple. Cashew apple juice was found to contain the highest amount of vitamin C (203.5 mg/100 ml) of edible portion. Orange, grape, pineapple, mango and lemon contained average values of 54.7 mg, 45.0 mg, 14.70 mg, 30.9 mg and 33.7 mg vitamin C per 100 ml of juice respectively. Obviously, cashew apple juice contains almost four times the amount of vitamin C in the popular citrus fruits and more than four times as much vitamin C as in other fruits. Hence, when cashew apple was blended with other tropical fruits it boosted their nutritional quality. On the other hand, these fruits improved the acceptability of cashew juice in terms of taste and flavour. The blends, even though significantly different (P <0.05) in taste, colour and mouthfeel, were all acceptable to consumers with no significant difference (P>0.05) in overall acceptability. Received: 16 August 1999 / Revised version: 2 November 1999     

热带水果混合果酱的研制

利用非洲布隆迪盛产的香蕉,配梧木瓜,芒果等其它热带水果,经科学试验,制定了合理的配方和制作工艺,开发出受欢迎的果酱产品。     

In vitro availability of minerals of some tropical and citrus fruits as influenced by antinutritional factors

Four tropical fruits and three citrus fruits were analyzed for moisture, ash, antinutritional factors (phytate, oxalate, and polyphenols) contents, and total and available minerals. Moisture contents ranged from 6.0 to 83.17% for tropical fruits while that of citrus fruits ranged from 88.20 to 89.50%. Ash contents ranged from 2.56 to 4.50% and from 3.83 to 4.83%, for tropical and citrus fruits, respectively. All fruits contained no oxalate while phytate and polyphenols ranged from 48.1 to 134.1 mg/ 100 g and from 0.115 to 0.34%, respectively. For all fruits major minerals contents ranged from 7.7 to 433.3 while trace ones ranged from 0.116 to 1.91 mg/100 g. In vitro availabilities of major minerals (% of total) varied from 11.1 to 86.2% while for minor ones it ranged from 13 to 72.5%.     

Chemical composition of fruits in some rose (Rosa spp.) species

Fruits of Rosa canina, Rosa dumalis subsp. boissieri, Rosa dumalis subsp. antalyensis, Rosa villosa, Rosa pulverulenta and Rosa pisiformis were assayed for total phenolics, ascorbic acid, total soluble solids, total dry weight, total fat, fatty acids, pH, acidity, moisture, fruit colour and macro- and micro-elements. The highest total phenolic content was observed in Rosa canina (96 mg GAE/g DW). Rosa dumalis subsp. boissieri had the highest total fat content (1.85%), followed by Rosa pulverulenta (1.81%) and Rosa canina (1.78%), respectively. Nine major fatty acids were determined in rose species and α-linolenic acid was found to be dominant for all species. Total soluble solids, total dry weight, moisture and ascorbic acid contents of rose species varied from 29.42% (Rosa villosa)–37.33% (Rosa dumalis subsp. boissieri), 33.85% (Rosa villosa)–40.35% (Rosa dumalis subsp. boissieri), 59.65% (Rosa dumalis subsp. boissieri)–66.15% (Rosa villosa) and 727 mg/100 g FW (Rosa villosa) and 943 mg/100 g FW (Rosa dumalis subsp. boissieri), respectively. Nitrogen and mineral compositions of the rose species, e.g., N, P, K, Ca and Mg, were (averagely): 1.26%, 513 mg/100 g DW, 639 mg/100 g DW, 196 mg/100 g DW and 114 mg/100 g DW, respectively. The present study shows that the native rose genotypes are extremely rich sources of phenolics, carbohydrates and ascorbic acid, demonstrating their potential use as a food or food additive.     

Antioxidant activity and profiles of common fruits in Singapore

Thirty-eight types of fruits commonly consumed in Singapore were systematically analysed for their hydrophilic oxygen radical absorbance capacity (H-ORAC), total phenolic content (TPC), ascorbic acid (AA) and various lipophilic antioxidants. Antioxidant composition and concentration varied widely across different fruits. Many of the tropical fruits tested were high in antioxidants. Amongst all fruits tested, sapodilla (Manilkara zapota) had the highest H-ORAC and TPC whilst guava had the highest AA per gram fresh weight. Papaya, red watermelon and cantaloupe had the highest β-cryptoxanthin, lycopene and β-carotene per gram fresh weight, respectively. On the other hand, durian and mangosteen were high in tocopherols and tocotrienols, respectively. Based on consumption data, Chinese Singaporeans appear to have a higher intake of carotenoids and tocopherols rich fruits compared to the US population. As fruits are a rich source of diverse antioxidants, efforts to promote consumption of a variety of fruits should be continued for public health benefits.     

Ozone-induced changes of antioxidant capacity of fresh-cut tropical fruits

The effect of ozone treatment on total phenol, flavonoid, and vitamin C content of fresh-cut honey pineapple, banana ‘pisang mas’, and guava was investigated. The fresh-cut fruits were exposed to ozone at a flow rate of 8 ± 0.2 ml/s for 0, 10, 20, and 30 min. The antioxidant capacity of the fruits was evaluated by measuring the ferric reducing/antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. Total phenol and flavonoid contents of pineapple and banana increased significantly when exposed to ozone for up to 20 min, with a concomitant increase in FRAP and DPPH values. The opposite was observed for guava. Ozone treatment significantly decreased the vitamin C content of all three fruits. The study shows promising results for enhancing antioxidant capacity of some fresh fruits by ozone treatment although the positive effect is compromised by a reduction in vitamin C content.Industrial relevanceThe preservation of antioxidant properties, storage stability and safety is of utmost importance in the minimally processed fresh food industry. Ozone has been looked into as an alternative sanitizing technology in the fresh produce industry. The results of this study indicate that ozone can be used in the minimally processed fresh food industry to enhance the antioxidant status of fresh-cut fruits.     

Vitamin C and carotenoids in organic and conventional fruits grown in Brazil

This study compared the concentration of vitamin C (ascorbic acid, AA, and dehydroascorbic acid, DHA) and carotenoids (lycopene and β-carotene) between three fruits produced by organic and conventional farming. Vitamin C and carotenoids were analysed by high-performance liquid chromatography. The Student t-test (α = 5%) was applied to determine differences between the organic and conventional production systems. AA content was significantly higher in organic acerola (4023.39 mg/100 g) compared to its conventional production (2294.53 mg/100 g). Conversely, AA content was significantly higher in conventional strawberries (42.45 mg/100 g) than the organic ones (30.74 mg/100 g). The conventional production also showed significantly higher contents of DHA (persimmon: 7.50 mg/100 g vs. 0.96 mg/100 g) and β-carotene (acerola: 6130.24 μg/100 g vs. 2486.38 μg/100 g) than the organic fruits. Lycopene was only detected in persimmons, but no significant difference was observed between farming systems. There was no evidence of the nutritional superiority of the organically grown fruits.     

UV radiation-induced changes of antioxidant capacity of fresh-cut tropical fruits

The effect of ultraviolet (UV-C) treatment on total phenol, flavonoid, and vitamin C content of fresh-cut honey pineapple, banana “pisang mas”, and guava was investigated. The antioxidant capacity of the fruit also was evaluated by measuring its ferric reducing/antioxidant power (FRAP) and DPPH free radical-scavenging activity. The fresh-cut fruits were exposed to UV-C for 0, 10, 20, and 30 min. Total phenol and flavonoid contents of guava and banana increased significantly with the increase in treatment time. In pineapple, the increase in total phenol content was insignificant, but the flavonoid content increased significantly after 10 min of treatment. UV-C treatment decreased the vitamin C content of all three fruits. In fresh-cut banana, longer treatment time resulted in higher FRAP and DPPH values; these values remained stable throughout the experiment for fresh-cut pineapple. For fresh-cut guava, FRAP and DPPH values were stable until 30 min, after which a significant increase in FRAP values occurred.

Industrial relevance

UV irradiation processing of fresh-cut fruits leads to increase in antioxidants, polyphenols, and flavonoids. Hence, apart from the application of UV for microbial safety at industrial levels, this novel technology can also be exploited for enhancement of health promoting compounds for benefit of consumers.     

Antioxidant properties of several tropical fruits: A comparative study

Nine tropical fruits were analyzed for total phenol contents, ascorbic acid contents and antioxidant activities. The antioxidant activities were evaluated based on the ability of the fruit extracts to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), reduce iron(III) to iron(II) and to bind to iron(II) ions. The results were compared to those of orange. It was found that guava, papaya and star fruit have higher primary antioxidant potential, as measured by scavenging DPPH and iron(III) reducing assays. Banana, star fruit, water apple, langsat and papaya have higher secondary antioxidant potential as measured by the iron(II) chelating experiment.     

Free radical scavenging behavior of ten exotic tropical fruits extracts

The antiradical capacity (radical scavenger capacity, RSC) of bacuri, cajá, camu-camu, carnauba, gurguri, jabuticaba, jambolão, juçara, murta, black puçá and puçá were studied using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) assay. To determine their RSC, the second-order rate constants (k₂) for the oxidation of these extracts by DPPH• were calculated. The values of k₂ were compared to natural and synthetic antioxidants. The k₂ values (L/mol g s), in methanol at 25 °C, were 69.52, 26.03, 22.20, 18.04, 17.23, 16.56, 15.60, 10.03, 7.72 and 4.15 for camu-camu, murta, gurguri, carnauba, jabuticaba, black puçá, jambolão, cajá, juçara and bacuri.     

Effect of permeable coatings on the storage life of fruits.

A permeable membrane coating can be produced on fruit surfaces by dipping in an aqueous dispersion of Pro-long, a mixture of sucrose esters of fatty acids and the sodium salt of carboxymethylcellulose. Mangoes (Mangifera indica L. cv. Julie) were treated with 0.75 and 1.0% w/v aqueous suspensions of Pro-long and stored at 252°C/85–95% RH. Treatment with 0.75% Pro-long significantly increased the storage life of mangoes, retarding ripening and reducing weight loss, without adversely affecting the sensory quality of the fruit. Treatment at 1% resulted in increased ethanol formation in the pulp of some mangoes.