Total and individual carotenoid profiles in Solanum phureja of cultivated potatoes: I. Concentrations and relationships as determined by spectrophotometry and HPLC

Total and individual carotenoid concentrations were determined by spectrophotometry and HPLC, in raw tubers of a sample of 23 accessions of Solanum phureja potatoes taken at random from the world germplasm collection following its stratification on tuber flesh color. Lutein, zeaxanthin, violaxanthin, antheraxanthin and β-carotene were detected in all accessions and three distinct patterns of carotenoid accumulation were evidenced by cluster analysis. Accessions in group 1 showed the highest concentrations of total carotenoids (1258–1840 μg 100 g⁻¹ FW) comprised largely of zeaxanthin (658–1290 μg 100 g⁻¹ FW) with very low or no presence of β-carotene (below 5.4 μg 100 g⁻¹ FW). Accessions in group 2 presented moderate total carotenoid concentrations with violaxanthin, antheraxanthin, lutein and zeaxanthin as the major carotenoids. Accessions in group 3 showed low concentrations of total carotenoids (97–262 μg 100 g⁻¹ FW) and very low or no zeaxanthin, with lutein and violaxanthin as the predominant carotenoids and relatively high concentrations of β-carotene (up to 27 μg 100 g⁻¹ FW). Five accessions with significant concentrations of zeaxanthin were identified with the accession 703566 showing the highest concentration (1290 μg 100 g⁻¹ FW). This value is to our knowledge higher than any value previously reported for potatoes, including those achieved through genetic modification. For the 23 S. phureja accessions, total carotenoid concentration was positively and significantly correlated with antheraxanthin and zeaxanthin concentrations, and negatively and significantly correlated with β-carotene concentration.     

Genetic diversity of nutritionally important carotenoids in 94 pea and 121 chickpea accessions

Biofortification of staple crops via breeding is an attractive strategy for reducing human micronutrient deficiencies. The objective of this research was to examine the concentration of carotenoids in diverse pea and chickpea accessions grown in Saskatchewan (Canada) using high performance liquid chromatography. In pea accessions mean concentration of lutein was highest (11.2 μg g⁻¹) followed by β-carotene (0.5 μg g⁻¹), zeaxanthin (0.3 μg g⁻¹), and violaxanthin (0.3 μg g⁻¹). Green cotyledon pea accessions were richer in β-carotene and total carotenoids compared to yellow cotyledon accessions. In chickpea accessions mean concentration of lutein (8.2 μg g⁻¹) was highest followed by zeaxanthin (6.2 μg g⁻¹), β-carotene (0.5 μg g⁻¹), β-cryptoxanthin (0.1 μg g⁻¹), and violaxanthin (0.1 μg g⁻¹). Desi chickpea accessions had higher carotenoid concentration than kabuli accessions. This research identified pea and chickpea accessions that can be utilized in breeding for the improvement of carotenoid concentration through biofortification.     

Influence of Age, Farming Site, and Boiling on Pro-Vitamin A Content in Sweet Potato (Ipomoea batatas(L.) Lam.) Storage Roots

To maximize the availability of pro-vitamin A carotenoids in sweet potato and to recommend the appropriate start of piecemeal harvesting practice, the main carotenoids in storage roots of 17 different sweet potato cultivars were surveyed using HPLC and spectrophotometry methods, and their variation due to production site, storage root age, and boiling was assessed. There was significant variation in carotenoid content among cultivars. Six different carotenoids were consistently detected in significant quantities. Orange-fleshed roots contained higher total carotenoid and β-carotene content than white- and cream-fleshed lines, and alltrans-β-carotene predominated. The effect of storage root age on carotenoid content was significant. Twelve weeks after planting, the yield and amount of pro-vitamin A present in roots of orange-fleshed cultivars evaluated were high enough to provide adequate dietary pro-vitamin A and suggest the start of piecemeal harvesting. The effect of farming site on total carotenoids was significant; however, the amount of β-carotene was not different over three testing sites. Boiling of roots for 30 min caused a reduction in total carotenoids which varied by cultivar; however, further boiling for up to 60 min did not exacerbate the reduction in total carotenoids.     

Phenolic content and antioxidant capacity of Philippine potato (Solanum tuberosum) tubers

Four potato (Solanum tuberosum) varieties – Bengueta, Ganza, Igorota and 125411.22 – were analyzed for total phenolic content and antioxidant activities to provide baseline data for Philippine potato varieties. Bengueta had the highest phenolic content with 50.0 ± 1.5 mg gallic acid equivalent (GAE)/100 g (dry basis, DB). It also had the highest DPPH radical scavenging activity with an EC₅₀ value of 30.6 ± 3.6 mg/mL (DB). The potato variety125411.22 had the highest reducing power with EC₅₀ equal to 66.2 ± 1.6 mg/mL (DB), while Igorota had the highest iron-chelating capacity with an EC₅₀ of 11.0 ± 3.2 mg/mL (DB) and the best inhibitory action against linoleic acid oxidation at 95.4 ± 2.2% at 50 mg/mL sample concentration. Methanolic potato extracts had better antioxidant activity than α-tocopherol and better iron chelating capacity than ethylenediamine tetraacetic acid (EDTA). Significant (^*P < 0.05) negative correlation (R = −0.542) was observed between total phenolic content and the EC₅₀ values for DPPH radical scavenging activity, but none between total phenolic content and reducing power, iron-chelating capacity and total antioxidant activity.     

Fruit and Vegetable Intake Assessed by Food Frequency Questionnaire and Plasma Carotenoids: A Validation Study in Adults

Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence.     

Food Predictors of Plasma Carotenoids

Empirical prediction models that weight food frequency questionnaire (FFQ) food items by their relation to nutrient biomarker concentrations may estimate nutrient exposure better than nutrient intakes derived from food composition databases. Carotenoids may especially benefit because contributing foods vary in bioavailability and assessment validity. Our objective was to develop empirical prediction models for the major plasma carotenoids and total carotenoids and evaluate their validity compared with dietary intakes calculated from standard food composition tables. 4180 nonsmoking women in the Nurses’ Health Study (NHS) blood subcohort with previously measured plasma carotenoids were randomly divided into training (n = 2787) and testing (n = 1393) subsets. Empirical prediction models were developed in the training subset by stepwise selection from foods contributing ≥0.5% to intake of the relevant carotenoid. Spearman correlations between predicted and measured plasma concentrations were compared to Spearman correlations between dietary intake and measured plasma concentrations for each carotenoid. Three to 12 foods were selected for the α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene, and total carotenoids prediction models. In the testing subset, Spearman correlations with measured plasma concentrations for the calculated dietary intakes and predicted plasma concentrations, respectively, were 0.31 and 0.37 for α-carotene, 0.29 and 0.31 for β-carotene, 0.36 and 0.41 for β-cryptoxanthin, 0.28 and 0.31 for lutein/zeaxanthin, 0.22 and 0.23 for lycopene, and 0.22 and 0.27 for total carotenoids. Empirical prediction models may modestly improve assessment of some carotenoids, particularly α-carotene and β-cryptoxanthin.     

New data on the carotenoid composition of raw salad vegetables

This study was carried out to determine the concentrations of the principal carotenoids of eight vegetables (Nantes carrot, chicory, Boston and curly lettuce, green bell pepper, rucula, Carmen tomato and cress), which are the most consumed in raw salad by the Brazilian population. The samples were purchased from three major supermarkets in the city of Sao Paulo. For each vegetable, six composite samples collected at different times during the year were analyzed individually. The green vegetables had lutein (7.7–56.1 μg/g), β-carotene (2.7–35.3 μg/g), violaxanthin (4.6–31.7 μg/g) and neoxanthin (3.1–20.5 μg/g) as principal carotenoids. Boston and curly lettuce also contained lactucaxanthin (7.5 and 6.7 μg/g, respectively). Carrot had α-carotene (35.0 μg/g) and β-carotene (61.5 μg/g) as principal carotenoids and lutein (5.1 μg/g) as minor component. Tomato, a rich source of lycopene (35.4 μg/g), also contained lutein (1.0 μg/g) and β-carotene (3.2 μg/g) in much smaller amounts.     

Phytoremediation of fungicides by aquatic macrophytes: Toxicity and removal rate

The rate of removal of two fungicides (dimethomorph and pyrimethanil) from water by five macrophyte species (L. minor, S. polyrhiza, C. aquatica, C. palustris and E. canadensis) was assessed in laboratory tests. In order to assure that these studies were performed with healthy plants the effects of the fungicides on chlorophyll fluorescence were studied as well. At exposure concentrations of 600 μg L⁻¹ the effects of the fungicides on chlorophyll fluorescence were minor, so that this initial concentration level was selected for the fungicide removal rate tests. The removal yields during the 4-d test periods varied from 10% to 18% and 7% to 12% for dimethomorph and pyrimethanil, respectively. The maximum removal rate during the 4-d test period was 48 μg g⁻¹ fresh weight (FW) for dimethomorph and 33 μg g⁻¹ FW for pyrimethanil. L. minor and S. polyrhiza showed the highest removal efficiency for the two fungicides.     

Application of NIR and MIR spectroscopy in quality control of potato chips

The feasibility of developing a technique for rapid monitoring of potato chip quality by using infrared spectroscopy combined with multivariate analysis was investigated. Spectra of 15 commercial potato chips were collected by using an integrating sphere (near-infrared, NIR) or attenuated total reflectance (mid-infrared, ATR-MIR) accessories. Oil from potato chips was extracted with a carver press and spectra were collected by using a temperature controlled ATR accessory. The moisture and fat content were analyzed with reference methods AOAC #984.25 and AOAC #963.15, respectively. The spectral data were analyzed by partial least squares regression (PLSR) and calibration models generated. Fat content ranged from 18 to 45%, and moisture content ranged from 1.2 to 4%. Correlation coefficient (r) for moisture was >0.97 with standard error of cross validation (SECV) < 0.3% for both NIR and MIR techniques. Prediction models for fat had r > 0.96 and SECV < 1.60 for both NIR and MIR. Classification model based on Soft Independent Modeling of Class Analogy (SIMCA) differentiated potato chips by source of frying oil. MIR spectroscopy identified samples containing -trans fatty acids at 967 cm⁻¹. A fast, simple and accurate method to evaluate potato chip quality was developed by using infrared spectroscopy.     

Dietary Intake and Circulating Concentrations of Carotenoids and Risk of Type 2 Diabetes: A Dose-Response Meta-Analysis of Prospective Observational Studies

Previous meta-analysis studies have indicated inverse associations between some carotenoids and risks of metabolic syndrome, cardiovascular disease, cancer, and all-cause mortality. However, the results for associations between carotenoids and type 2 diabetes (T2D) remain inconsistent and no systematic assessment has been done on this topic. We conducted a systematic review and meta-analysis to examine the associations of dietary intakes and circulating concentrations of carotenoids with risk of T2D. We searched PubMed and Ovid Embase from database inception to July 2020. Prospective observational studies of carotenoids and T2D risk were included. Random-effects models were used to summarize the RRs and 95% CIs. Thirteen publications were included. Dietary intake of β-carotene was inversely associated with the risk of T2D, and the pooled RR comparing the highest with the lowest categories was 0.78 (95% CI: 0.70, 0.87; I² = 13.7%; n = 6); inverse associations were also found for total carotenoids (n = 2), α-carotene (n = 4), and lutein/zeaxanthin (n = 4), with pooled RRs ranging from 0.80 to 0.91, whereas no significant associations were observed for β-cryptoxanthin and lycopene. Circulating concentration of β-carotene was associated with a lower risk of T2D, and the pooled RR comparing extreme categories was 0.60 (95% CI: 0.46, 0.78; I² = 56.2%; n = 7); inverse associations were also found for total carotenoids (n = 3), lycopene (n = 4), and lutein (n = 2), with pooled RRs ranging from 0.63 to 0.85, whereas no significant association was found for circulating concentrations of α-carotene and zeaxanthin when comparing extreme categories. Dose-response analysis indicated that nonlinear relations were observed for circulating concentrations of α-carotene, β-carotene, lutein, and total carotenoids (all P-nonlinearity < 0.05), but not for other carotenoids or dietary exposures. In conclusion, higher dietary intakes and circulating concentrations of total carotenoids, especially β-carotene, were associated with a lower risk of T2D. More studies are needed to confirm the causality and explore the role of foods rich in carotenoids in prevention of T2D.This systematic review was registered at www.crd.york.ac.uk/prospero as CRD42020196616.     

Evaluation of the Maillard reaction in potato crisps by acrylamide, antioxidant capacity and color

This study aimed at examining potential risks and benefits associated with the frying process for potato crisps. The effects of reducing sugars, frying temperature and time on acrylamide and total antioxidant capacity (TAC) of potato crisps were studied. TAC of potato crisps ranged between 13 and 68 mmol Trolox Eq./kg, depending on the sugar concentration and frying conditions. Acrylamide and TAC variables correlated very well for potato crisps (r = 0.8322). There was also close linear correlation between CIE (Commission Internationale de l’Eclairage) a* and TAC values of potato crisps fried at different time–temperature conditions with different initial sugar concentrations. Similar to the CIE a*, the total color difference (ΔE) also showed a high correlation with acrylamide (r = 0.7870) and TAC (r = 0.7678). Acrylamide and TAC of potato crisps appeared less sensitive to a variation in lightness (L*) having correlation coefficients of 0.7302 and 0.7630, respectively. On the other hand, CIE b* values had lack of correlation with acrylamide (r = 0.2612) and TAC (r = 0.3503) of potato crisps.     

Distribution of Free Seleno-amino Acids in Plant Tissue ofMelilotus indicaL. Grown in Selenium-Laden Soils

Accumulation of specific groups of seleno-amino acids in plant tissue reflects not only the Se tolerance of a plant species, but also Se toxicity to animals. The distribution of seleno-amino acids in a Se-tolerant grassland legume species (Melilotus indicaL.) grown in Se-laden soils was studied using high-resolution gas chromatography-and gas chromatography-mass spectrometry. Five seleno-amino acids including selenocystine, selenomethionine, selenocysteine, Se-methylselenocystine, andγ-glutamyl-Se-methylselenocysteine were identified and measured for their plant tissue concentrations. Se-methylselenocysteine, a nonprotein seleno-amino acid, was found in the plant tissue. Its concentration ranged from 15.3 μmol kg⁻¹for the plants growing in soil of low Se concentration to 109.8 μmol kg⁻¹for the plants grown in soil of high Se concentration. Accumulation of the nonprotein seleno-amino acid in this species resembles that in Se accumulator plants.γ-Glutamyl-Se-methylselenocysteine was detected in the plant. However, its concentration was very low. It might not become a toxic element in the food chain. Results of plant tissue Se accumulation analysis indicated that there was a five-fold increase in tissue selenocysteine concentration when the total tissue Se increased from 5.07 to 22.02 mg kg⁻¹, but there was no further increase in tissue selenocysteine concentration when the tissue total Se concentration increased from 22.0 to 117.4 mg kg⁻¹. Selenomethinone constituted more than 50% of the total seleno-amino acid in the plant. More research is needed to reveal whether the mechanisms limiting the accumulation of selenocysteine and preferential accumulation of selenomethionine found in this study play any role in Se tolerance in this species.     

Evolution of benzoate derivatives and their hydroxycinnamate analogues during ageing of white wines in oak barrels

Two white wines produced industrially, originating from the V. vinifera cultivars Asyrtiko and Chardonnay, were monitored with regard to the evolution of selected phenolic acids, during “on lees” ageing in oak casks for a period of 197 days. Four benzoic acid derivatives, namely p-hydroxybenzoic acid, protocatechuic acid, vanillic acid and syringic acid, and their corresponding hydroxycinnamate analogues p-coumaric acid, caffeic acid, ferulic acid and sinapic acid, were considered. The most abundant benzoate and hydroxycinnamate derivatives were protocatechuic acid and caffeic acid, with concentrations varying from 0.31 to 0.42 μg mL⁻¹ and 1.71 to 2.47 μg mL⁻¹, respectively, while the profile of both phenolic categories was essentially the same in both wines. The evolution pattern of benzoates showed that maximum concentration of protocatechuic acid was achieved after approximately 100 days (0.45–0.48 μg mL⁻¹) of ageing for both samples, whereas all other compounds exhibited an increasing trend towards the end of the examination period. The concentration of all hydroxycinnamates increased at the end of ageing, from 49.4% (caffeic acid) to 123% (p-coumaric acid), to the exception of sinapic acid which underwent practically no changes.     

Carotenoid Biosynthetic and Catabolic Pathways: Gene Expression and Carotenoid Content in Grains of Maize Landraces

Plant carotenoids have been implicated in preventing several age-related diseases, and they also provide vitamin A precursors; therefore, increasing the content of carotenoids in maize grains is of great interest. It is not well understood, however, how the carotenoid biosynthetic pathway is regulated. Fortunately, the maize germplasm exhibits a high degree of genetic diversity that can be exploited for this purpose. Here, the accumulation of carotenoids and the expression of genes from carotenoid metabolic and catabolic pathways were investigated in several maize landraces. The carotenoid content in grains varied from 10.03, in the white variety MC5, to 61.50 μg·g⁻¹, in the yellow-to-orange variety MC3, and the major carotenoids detected were lutein and zeaxanthin. PSY1 (phythoene synthase) expression showed a positive correlation with the total carotenoid content. Additionally, the PSY1 and HYD3 (ferredoxin-dependent di-iron monooxygenase) expression levels were positively correlated with β-cryptoxanthin and zeaxanthin, while CYP97C (cytochrome P450-type monooxygenase) expression did not correlate with any of the carotenoids. In contrast, ZmCCD1 (carotenoid dioxygenase) was more highly expressed at the beginning of grain development, as well as in the white variety, and its expression was inversely correlated with the accumulation of several carotenoids, suggesting that CCD1 is also an important enzyme to be considered when attempting to improve the carotenoid content in maize. The MC27 and MC1 varieties showed the highest HYD3/CYP97C ratios, suggesting that they are promising candidates for increasing the zeaxanthin content; in contrast, MC14 and MC7 showed low HYD3/CYP97C, suggesting that they may be useful in biofortification efforts aimed at promoting the accumulation of provitamin A. The results of this study demonstrate the use of maize germplasm to provide insight into the regulation of genes involved in the carotenoid pathway, which would thus better enable us to select promising varieties for biofortification efforts.     

Transfer of nodularin to three-spined stickleback (Gasterosteus aculeatus L.), herring (Clupea harengus L.), and salmon (Salmo salar L.) in the northern Baltic Sea

Nodularin (NODLN) is a hepatotoxin produced by the cyanobacterium Nodularia spumigena, which occurs regularly in the Baltic Sea. The primary aim of this study was to study the transfer of NODLN to three-spined stickleback (Gasterosteus aculeatus L.), herring (Clupea harengus membras L.), and salmon (Salmo salar L.), which were caught from the northern Baltic Sea between August 2002 and August 2003. Liquid chromatography mass spectrometry (LC-MS) was used for NODLN analysis. NODLN was found in both herring (0–90 μg kg⁻¹ dw) and three-spined sticklebacks samples (2.8–700 μg kg⁻¹ dw). The recovery for the spiked stickleback samples in vitro was 28%. Only 1 salmon of a total of 10 contained a small amount of NODLN (10 μg kg⁻¹ dw). However, the high concentrations in individual stickleback suggest that possible transfer to higher trophic levels deserves more research.     

Carotenoids and ascorbic acid composition from commercial products of cashew apple (Anacardium occidentale L.)

Carotenoids were determined by high-performance liquid chromatography (HPLC) and ascorbic acid (AA) by the official method of the Association of Official Analytical Chemists (AOAC) in cashew apple products found on the market of Campinas, Brazil. The following products, concentrated juice, frozen pulp, nectar, ready-to-drink, and sweetened concentrated juice, were analyzed, showing AA contents from 13.7 to 121.7 mg/100 g and total carotenoid levels ranging from 8.2 to 197.8 μg/100 g. β-Carotene was the main carotenoid in the majority of the products, followed by α-carotene, β-cryptoxanthin and 9-cis- +13-cis-β-carotene in similar proportions. However, in 10 of the 60 samples analyzed, another carotenoid pattern was found with the presence of auroxanthin, 5,8-epoxy-cryptoxanthin, 5,8-epoxy-lutein, ζ-carotene and two unidentified carotenoids. Cashew apple products were proved to be excellent sources of vitamin C, but not very good sources of carotenoids for the human diet.     

Relationship between Carotenoids,Retinol, and Estradiol Levels in Older Women

Background. In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. Methods. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998–2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. Results. After adjustment for age, α-carotene (β ± SE = −0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = −0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = −1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = −0.29 ± 0.08, p = 0.0009), and E2 persisted whereas the relationship between α-carotene and T/E2 ratio was attenuated (β ± SE = 0.22 ± 0.12, p = 0.07). In a fully adjusted model (Model 3), only β-carotene (β ± SE = −0.05 ± 0.02, p = 0.03) was significantly and inversely associated with E2 levels independent of α-carotene. No association was found between retinol, total non-pro-vitamin A carotenoids, lutein, zeaxanthin, and lycopene, and E2 levels. Conclusions: In older women, β-carotene levels are independently and inversely associated with E2.     

Carotenoid database of commonly eaten Swiss vegetables and their estimated contribution to carotenoid intake

Carotenoids are plant pigments which are thought to decrease the risk of degenerative diseases via their antioxidant properties. The aim of this work was to create a carotenoid database for clearly identified Swiss vegetables, grown under known conditions and analyzed using a standardized protocol. We determined the six major carotenoids in the vegetables most frequently consumed in Switzerland. Chlorophyll a and b were additionally measured in green leafy vegetables. Lutein and β-carotene concentrations in green leafy vegetables ranged from 0.2 to 13 mg and 0.2 to 8 mg/100 g fresh matter, respectively, with the highest total carotenoid contents in Brassicaceae. Additionally, we identified strong correlations (R² > 0.9) between the lutein and β-carotene concentrations and the total chlorophyll contents in different botanical families. Orange and red vegetables contained a greater diversity of carotenoids, with α- and β-carotene being the predominant carotenoids in orange carrots and lycopene in tomatoes. Peppers additionally contained zeaxanthin and β-cryptoxanthin. Based on these data, and on the estimated consumption of the different vegetables in Switzerland, we estimate that 3.3 mg β-carotene, 2.2 mg lycopene and 1.8 mg lutein are consumed daily from fresh vegetables.     

Influence of process variables on colour changes, carotenoids retention and cellular tissue alteration of cherry tomato during osmotic dehydration

Osmotic dehydration is an appropriate technique for preserving nutritional components that are naturally present in different vegetables. In order to quantitatively evaluate changes induced by osmotic treatment in CIEL*a*b* colorimetric parameters and lycopene and β-carotene content, cherry tomato in halves (L. esculentum var. cerasiforme cv. Cocktail) were osmotically treated by immersion in different solutions (a 20% w/w, NaCl solution, a 55 Brix sucrose solution and a ternary solution (10% NaCl and 27.5% sucrose)) at 30, 40 and 50 °C for 24 h. The alteration suffered by the cellular tissue was also analysed by means of microscopic observations. The obtained results showed a general increase in a* and b* coordinates resulting from the concentration of the liquid phase and a decrease in lightness as a consequence of the enhancement in sample opacity. Regarding carotenoids content, an increase in lycopene and β-carotene was observed in samples osmotically dehydrated at moderate temperatures (30 °C and 40 °C) with the solutions that include sucrose on its composition. In addition, microscopic observations revealed a direct relationship between the integrity of the cellular matrix and the preservation or even synthesis of lycopene and β-carotene.     

Toxicity and removal of heavy metals (cadmium, copper, and zinc) by Lemna gibba

Effects of cadmium, copper, and zinc on the aquatic plant Lemna gibba were determined under controlled conditions; in parallel their removal from the growth medium was followed. The results showed that the three heavy metals affected growth, a physiological stress index defined as the ratio of Chlorophyll to phaeophytin (D665/D665a), and the contents of proline. After 4 days, 10⁻³–10⁻¹ mg/L Cd inhibited growth by 25–100%, reduced D665/D665a by 35–89%, and increased proline content by 44–567%. Under the same conditions, 10⁻⁴–10⁻¹ μg/L Cu inhibited growth by 36–75%, reduced D665/D665a by 19–81%, and increased proline content by 67–288%. Comparable concentrations of Zn had little effect. However, higher concentrations (4, 30, and 50 mg/L) inhibited growth by 50–79%. Also, 0.1 and 30 mg/L induced a small reduction of D665/D665a (−3.8% and −22%) and an increase in proline contents (+144% and +177%). When it was observed, proline accumulation was always transient and the maximum was reached after 4 days. Monitoring metal concentration in the medium showed that L. gibba was able to remove metals from the medium. Zn and Cu removal was biphasic, it was rapid during the first 2 days (> 60% reduction) and slow (10–20%) during the following 8 days. For Cd, removal was linear and depended on the initial concentration. It reached approximately 90% after 6 or 8 days for initial concentrations of 10⁻¹ and 10⁻³ mg/L, respectively.