High Vitamin C Research Articles

The effect of cold plasma treatment on the fruit quality and aroma components of winter jujubes (Ziziphus jujuba Mill. 'Dongzao').

Cold plasma (CP) is a novel environmental-friendly preservation technology that causes minimal damage to fruits. The flavor and quality of winter jujubes have decreased with the extended storage time. Currently, the research on the use of CP on winter jujubes (Ziziphus jujuba Mill. 'Dongzao') mainly focuses on the effect of the treatment on storage quality. There is limited research on the effect of CP treatment on the flavor of winter jujubes. This study used different CP (80kV) treatment durations (0, 5, and 10min) to treat winter jujubes. The appropriate treatment time was selected by observing the changes in color, respiratory intensity, soluble sugar content, total acid content, and vitamin C (VC) content of winter jujubes. Amino acid analyzer and headspace solid-phase microextraction in combination with gas chromatography coupled with mass spectrometric detection were used to analyze the effect of CP treatment on the flavor compounds of winter jujubes. The results showed that the 5-min CP treatment could significantly slow down the red coloration of winter jujube while maintaining high soluble sugar, total acid, and VC content. At the respiration peak, the respiratory intensity of the 5-min CP treatment group was 0.74 mg CO2·kg-1·h-1 lower than that of the control group (p < 0.05). CP treatment slowed down the decrease in the content of amino acids and volatile organic compounds (such as 2-methyl-4-pentenal, 2-hexenal, and 3-hexenal) in winter jujubes. This study will provide basic data for applying CP preservation technology in postharvest winter jujubes.

Genomes of diverse Actinidia species provide insights into cis-regulatory motifs and genes associated with critical traits

BackgroundKiwifruit, belonging to the genus Actinidia, represents a unique fruit crop characterized by its modern cultivars being genetically diverse and exhibiting remarkable variations in morphological traits and adaptability to harsh environments. However, the genetic mechanisms underlying such morphological diversity remain largely elusive.ResultsWe report the high-quality genomes of five Actinidia species, including Actinidia longicarpa, A. macrosperma, A. polygama, A. reticulata, and A. rufa. Through comparative genomics analyses, we identified three whole genome duplication events shared by the Actinidia genus and uncovered rapidly evolving gene families implicated in the development of characteristic kiwifruit traits, including vitamin C (VC) content and fruit hairiness. A range of structural variations were identified, potentially contributing to the phenotypic diversity in kiwifruit. Notably, phylogenomic analyses revealed 76 cis-regulatory elements within the Actinidia genus, predominantly associated with stress responses, metabolic processes, and development. Among these, five motifs did not exhibit similarity to known plant motifs, suggesting the presence of possible novel cis-regulatory elements in kiwifruit. Construction of a pan-genome encompassing the nine Actinidia species facilitated the identification of gene DTZ79_23g14810 specific to species exhibiting extraordinarily high VC content. Expression of DTZ79_23g14810 is significantly correlated with the dynamics of VC concentration, and its overexpression in the transgenic roots of kiwifruit plants resulted in increased VC content.ConclusionsCollectively, the genomes and pan-genome of diverse Actinidia species not only enhance our understanding of fruit development but also provide a valuable genomic resource for facilitating the genome-based breeding of kiwifruit.

Association between the relative abundance of phyla actinobacteria, vitamin C consumption, and DNA methylation of genes linked to immune response pathways.

There is an emerging body of evidence that vitamin C consumption can modulate microbiota abundance and can also impact DNA methylation in the host, and this could be a link between diet, microbiota, and immune response. The objective of this study was to evaluate common CpG sites associated with both vitamin C and microbiota phyla abundance. Six healthy women participated in this cohort study. They were divided into two groups, according to the amount of vitamin C they ingested. Ingestion was evaluated using the 24-h recall method. The Illumina 450 k BeadChip was used to evaluate DNA methylation. Singular value decomposition analyses were used to evaluate the principal components of this dataset. Associations were evaluated using the differentially methylated position function from the Champ package for R Studio. The group with higher vitamin C (HVC) ingestion also had a higher relative abundance of Actinobacteria. There was a positive correlation between those variables (r = 0.84, p = 0.01). The HVC group also had higher granulocytes, and regarding DNA methylation, there were 207 CpG sites commonly related to vitamin C ingestion and the relative abundance of Actinobacteria. From these sites, there were 13 sites hypomethylated and 103 hypermethylated. The hypomethylated targets involved the respective processes: immune function, glucose homeostasis, and general cellular metabolism. The hypermethylated sites were also enriched in immune function-related processes, and interestingly, more immune responses against pathogens were detected. These findings contribute to understanding the interaction between nutrients, microbiota, DNA methylation, and the immune response.

Studies on Biodiversity and Physico-chemical Properties of Carambola (Averrhoa Carambola L.) in Nagaland

An experiment on the biodiversity and physicochemical properties of carambola (Averrhoa carambola was conducted in the Department of Horticulture, Nagaland University, SASRD, Medziphema Campus, Nagaland, India during February−April, 2021. 22 carambola genotypes were collected randomly from different locations (altitude 150−360 m MSL) of Dimapur district in Nagaland to identify the magnitude of variability and to study the plant morphological and biochemical properties of collected fruits. Ethnobotanical uses, medicinal and ayurvedic properties in different parts of carambola were documented by interrogation and questionaries from villagers during exploration. Majority of the genotypes were recorded to have spreading tree habit. The variation in fruit weight (84.66±38.72 g), fruit volume (66.32±33.33 cc), TSS (5.55±0.25° Brix), vitamin C content (26.57±6.77 mg 100 g-1), titratable acidity (0.29±0.13%), total sugar (8.32±1.44%), reducing sugar (7.62±1.33%) and oxalic acid (1.22±0.30%) was noted in different genotypes. The desirable characters with high heritability coupled with high genetic advance as percent of mean were recorded in fruit weight (98.20% and 92.52%), reducing sugar (97.40% and 36.05%), titratable acidity (99.90% and 92.97%) and oxalic acid (99.70% and 53.79%). Genotype-2 and Genotype-21 were considered as homogenous and more similar with less coefficient value (0.68) followed by Genotypes-13 and Genotypes-15 (2.10). Less acidity (0.19−0.20%), high Vitamin-C (37.87 mg 100 g-1 pulp) and high reducing sugar (9.28−9.45%) were noticed in Genotype-10 and Genotype-16 that stands as most promising genotypes in respect of biochemical composition of fruits.

A Causal Relationship between Vitamin C Intake with Hyperglycemia and Metabolic Syndrome Risk: A Two-Sample Mendelian Randomization Study.

Excessive oxidative stress can contribute to metabolic syndrome (MetS), and antioxidants can protect against its development. Vitamin C (VC) is a well-known antioxidant, and observational studies have associated a deficiency with an increased MetS risk. This study tested the hypothesis that dietary VC intake caused an inverse relation of MetS and its components risk using a two-sample Mendelian randomization (MR) method in adults ≥40 years in a city hospital-based (n = 58,701) and Ansan/Ansung plus rural (n = 13,598) cohorts. Independent genetic variants associated with dietary VC intake were explored using a genome-wide association study (GWAS) with significance levels of p < 5 × 10−5 and linkage disequilibrium (r2 threshold of 0.001), after adjusting for the covariates related to MetS, in a city hospital-based cohort (n = 52,676) excluding the participants having vitamin supplementation. MR methods, including inverse-variance weighting (IVW), weighted median, MR-Egger, and weighted model, were used to determine the causal relationship between the dietary VC intake and the risk of MetS and its components in Ansan/Ansung plus rural cohorts (n = 11,733). Heterogeneity and leave-one-out sensitivity analyses were conducted. Energy intake, as well as other nutrient intakes, were significantly lower in the low VC intake group than in the high VC intake group, but the incidence of MetS and its components, including hyperglycemia, hypertriglyceridemia, and hypertension, was observationally higher in inadequate low VC intake in the combined cohorts. In MR analysis, insufficient dietary VC intake increased the risk of MetS, hyperglycemia, hypertriglyceridemia, and hypertension in an IVW (p < 0.05). In contrast, only the serum fasting blood glucose concentration was significantly associated with VC intake in weight median analysis (p < 0.05), but there was no significant association of low dietary VC with MetS and its components in MR-Egger. There was no likelihood of heterogeneity and horizontal pleiotropy in MetS and its components. A single genetic variant did not affect their association in the leave-one-out sensitivity analysis. In conclusion, insufficient dietary VC intake potentially increased the MetS and hyperglycemia risk in Asian adults. Low VC intake can contribute to increasing type 2 diabetes incidence in Asians.

Vitamin C attenuates vancomycin induced nephrotoxicity through the reduction of oxidative stress and inflammation in HK-2 cells.

Oxidative stress is one of the possible mechanisms in vancomycin (VCM) induced nephrotoxicity. Some studies suggested that high dose Vitamin C (VC) has protective effect against the nephrotoxicity in mice, but the underlying molecular mechanism is not mentioned. We investigated the potential targets of high dose VC against oxidative stress and inflammation induced by VCM in renal tubular epithelial cells. We conducted an in vitro study using an immortalized proximal tubule epithelial cell line from a normal adult human kidney (HK-2). VCM added to HK-2 cells caused an increase of cell death, oxidative stress and expression of inflammatory cytokines. Co-treatment with 0.5 and 1 mM VC attenuated 4-8 mM VCM induced cell death and increased the cell viability to 58-90%. VC significantly decreased lipid peroxidation and increased superoxide dismutase activity. The upregulations of NF-κB, TNF-α and IL-6 in HK-2 cells under 4 mM VCM were also reversed by 0.5 mM VC through the inhibition of oxidative stress. This study showed for the first time that VC can attenuate the VCM induced nephrotoxicity by decreasing lipid peroxidation and expression of inflammatory cytokines, and increasing superoxide dismutase 2 (SOD2) activity, this effect may relate to the regulation of ROS/NF-κB pathway.

Different bio-chemical changes at low temperature storage on chilling injury and storage life of commercial cultivars of mango Mangifera indica L.

An experiment was conducted at Fruit Research Station, Sangareddy, Medak, Telangana to study the effect of low temperature storage on chilling injury and storage life of different commercial cultivars of mango (Mangifera indica L.) viz., Banganpalli, Dashehari, Peddarasam, Chinnarasam and Totapari stored at 8oC ± 1º C. The experimental design followed is completely randomized design with factorial concept with four replications per treatment.Various biochemical parameters like TSS, titratable acidity, ascorbic acid, reducing sugars, non reducing sugars and electrolyte leakage. The highest T.S.S. (15.35) was recorded in mango cv. Peddarasam, Among all interactions, the highest TSS (16.75) was recorded on 55th day with the mango cv. Peddarasam. The lowest acidity (0.70) was recorded in mango cv. Chinnarasam and the highest acidity (1.00) was recorded in cv. Totapari. The lowest brix acid ratio (10.04) was noticed in mango cv. Totapari. The highest (23.53) was recorded in mango cv. Peddarasam. The treated fruits were significantly influenced by low temperature with lowest reducing sugars (2.11) recorded in mango cv. Totapari. The highest total sugars (6.51) were recorded in mango cv. Peddarasam. The lowest total sugars (4.40) were recorded in mango cv. Totapari. The treated fruits differed significantly with highest vitamin-C (17.07) was recorded in mango cv Peddarasam while the lowest vitamin-C (9.67) recorded in mango cv. Banganpalli. The treated fruits differed significantly with lowest electrolyte leakage (13.85) recorded in mango cv. Totapari.

Studies on cultivation, nutrition and extracellular ligninolytic enzymes of Flammulina velutipes strains collected from Indian Himalayas

Seven different strains of Flammulina velutipes collected from the North East and North West Himalayas were evaluated for total protein and ligninolytic enzymes on wheat straw and malt extract liquid broth medium respectively. Nutritional analyses of 6 strains were also done followed with yield evaluation. Maximum mycelia protein was observed in strain DMRX-166 on the 20th day in malt extract medium and DMRX-768 and DMRX-769 in wheat straw medium. Minimum laccase production was observed in strain (DMRO-253). Laccase appearance starts on the 5 day of incubation and continuously increased upto 20th37th day. Highest peroxidase activity was observed in DMRX-897 in wheatstraw medium on 15 day followed by DMRO-253. In general, more peroxidase activity observed in wheat straw media as compared to malt extracts media. On the 15th day strain no. DMRX-1618 produced maximum ligninase activity (175 U/ml) followed by DMRX-1446 on malt extract medium. Wheat straw broth medium favored early lignin peroxidase activity on the 10th day in 3 strains while 4 strains produce more lignin peroxidase on the 20th day. Least lignin peroxidase activity was recorded inDMRX-897 in the malt extract medium. Manganese peroxidase was observed in DMRO-253 in malt extract medium. Nutritional analysis showed highest protein content in DMRX-1446 while highest vitaminC and D2th were found in DMRX-767. The current study elucidated enzyme and nutritional relationship with time will help for developing efficient cultivation practices in Flammulina in near future.

High dose vitamin C significantly reduces the nephrotoxicity of vancomycin in critically ill patients

To observe the changes of renal function in critically ill patients using vancomycin and analyze the renal protective effect of high dose vitamin C (VC) on vancomycin nephrotoxicity. Retrospective analysis was carried out to enroll the patients who were hospitalized in emergency intensive care unit (ICU) of Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2012 to October 2019. All patients were administered with vancomycin or VC infusion in addition. According to the infusion of vancomycin alone or in combination with VC, the patients were divided into vancomycin group and vancomycin in combination with VC group; vancomycin group was further divided into two groups according to before vancomycin or after vancomycin usage; combination group were further divided into two groups according to before VC use or after VC. The initial dosage of vancomycin was calculated according to the actual weight of the patient and adjusted according to the renal function. The dosage of VC was determined according to the disease severity of the patient, and the dosage range was 50-200 mg×kg-1×d-1, continuously infused into the body. The age, gender, weight and renal function etc. were recorded and analyzed. A total of 245 patients who met the requirements were included in the analysis. There were 127 patients in the vancomycin group and 118 patients in the combination group. The causes of patients admitted to ICU were pulmonary infection, sepsis, severe acute pancreatitis, etc. Among them, pulmonary infection accounted for 63.0% in vancomycin group, while severe acute pancreatitis accounted for 61.9% in combination group. The quick sequential organ failure assessment (qSOFA) score of combination group was significantly higher than that of vancomycin group [1.0 (0, 1.0) vs. 0 (0, 0.2), P < 0.01], its basic renal function was also significantly worse [serum creatinine (SCr, μmol/L): 98.0 (65.0, 178.2) vs. 56.0 (42.2, 71.0), blood urea nitrogen (BUN, mmol/L): 11.30 (6.48, 18.38) vs. 4.70 (3.45, 8.10), both P < 0.05], and the average daily dose of vancomycin was also significantly lower than that of vancomycin group (mg×kg-1×d-1: 23.0±9.4 vs. 26.6±8.5, P < 0.01). Compared with vancomycin before administration, the renal function was getting worse significantly after vancomycin administration [SCr (μmol/L): 68.0 (50.2, 104.5) vs. 56.0 (42.2, 71.0), BUN (mmol/L): 5.35 (3.75, 9.83) vs. 4.70 (3.45, 8.10), both P < 0.05]. Combination with VC significantly improved renal function compared with that before VC treatment [SCr (μmol/L): 79.0 (58.0, 129.0) vs. 98.0 (65.0, 178.2), P < 0.05; BUN (mmol/L): 9.60 (6.10, 18.30) vs. 11.30 (6.48, 18.38), P > 0.05] and shortened the length of ICU stay [days: 28.5 (14.8, 54.2) vs. 37.0 (25.0, 55.0), P < 0.01]. The incidence of drug-induced renal injury caused by vancomycin is high. Intravenous high dose VC can significantly reduce the nephrotoxicity of vancomycin and shorten the length of hospital stay. When vancomycin is used in critically ill patients, VC can be used in combination to reduce or avoid drug-induced renal injury, improve curative effect and reduce toxic effects.

High dose vitamin C inhibits proliferation of breast cancer cells through reducing glycolysis and protein synthesis

To investigate the effects of high dose vitamin C (VC) on proliferation of breast cancer cells and to explore its mechanisms. Human breast cancer cells Bcap37 and MDA-MB-453 were treated with VC at low dose (0.01 mmol/L), medium dose (0.10 mmol/L) and high dose (2.00 mmol/L). Cell proliferation was determined with CCK-8 assay, protein expression was evaluated by Western blot, and the secretion of lactic acid in tumor cells was detected by colorimetric method. Bcap37 cells were inoculated in nude mice, and tumor baring nude mice were intraperitoneally injected with high VC(4 g/kg, VC group, n=5)or normal saline (control group, n=5) for 24 d. Tumor weight and body weight were calculated. In vitro experiments demonstrated that high dose VC significantly inhibited cell proliferation in Bcap37 and MDA-MB-453 cells (all P<0.01); the expressions of Glut1 and mTOR signaling pathway-related proteins were decreased (all P<0.05); and the secretion of lactic acid was also markedly reduced (all P<0.05). In vivo experiment showed that the tumor weight was decreased in mice treated with high-dose VC as compared with control group (P<0.05), but no difference in body weights between two groups was observed. High dose VC may inhibit proliferation of breast cancer cells both in vitro and in vivo through reducing glycolysis and protein synthesis.

Evaluation of tomato fruit quality response to water and nitrogen management under alternate partial root-zone irrigation

A pot experiment was conducted to investigate the effects of different water and nitrogen supply amounts on the comprehensive assessment of tomato fruit quality and root growth parameters under alternate partial root-zone irrigation. Three upper irrigation limitations (i.e. 70% (W1), 80% (W2) and 90% (W3) of field capacity, respectively) and three N-fertilizer levels (i.e. 0.18 (N1), 0.30 (N2) and 0.42 (N3) g/kg soil, respectively) were arranged with a randomized complete block design, and alternate partial root-zone irrigation method was applied. Results showed that fruit yields under deficit irrigation (W1 and W2) were decreased by 6.9% and 2.0% respectively compared with W3 under N1 level. Yields of tomato under W1N1 and W1N2 combinations were also reduced by 10.3% and 7.2%, respectively compared with W1N3 combination. Root dry weight, root length, root surface area and root volume were all increased in W1N2 treatment. According to two-way ANOVA, the root parameters except root dry weight, were extremely sensitive to water, nitrogen and the cross effect of the two factors. TSS (total soluble solids), SS (soluble sugars) and OA (organic acid) in the fruits increased with the decrease in irrigation water, OA and NC reduced with decreasing amount of nitrogen. Moreover, within an appropriate range, as more irrigation water and nitrogen were applied, the higher VC (vitamin C) and lycopene contents were identified in the fruits. Eventually, the combinational evaluation method (i.e. entropy method and gray relational analysis) showed that W2N2 ranked highest in comprehensive fruit quality. Therefore, considering the tradeoff between fruit comprehensive quality and yields, upper irrigation limitation of 80% θf and N-fertilizer of 0.30 g/kg soil with alternate partial root-zone irrigation was the optimal cultivation strategy for the greenhouse tomato in autumn-winter season in northwest China. Keywords: greenhouse tomato, alternate partial root-zone irrigation, water and nitrogen, root growth, comprehensive fruit quality DOI: 10.25165/j.ijabe.20171005.2622 Citation: Yang H, Cao H X, Hao X M, Guo L J, Li H Z, Wu X Y. Evaluation of tomato fruit quality response to water and nitrogen management under alternate partial root-zone irrigation. Int J Agric & Biol Eng, 2017; 10(5): 85–94.

Glutathione Depletion, Pentose Phosphate Pathway Activation, and Hemolysis in Erythrocytes Protecting Cancer Cells from Vitamin C-induced Oxidative Stress

The discovery that oxidized vitamin C, dehydroascorbate (DHA), can induce oxidative stress and cell death in cancer cells has rekindled interest in the use of high dose vitamin C (VC) as a cancer therapy. However, high dose VC has shown limited efficacy in clinical trials, possibly due to the decreased bioavailability of oral VC. Because human erythrocytes express high levels of Glut1, take up DHA, and reduce it to VC, we tested how erythrocytes might impact high dose VC therapies. Cancer cells are protected from VC-mediated cell death when co-cultured with physiologically relevant numbers of erythrocytes. Pharmacological doses of VC induce oxidative stress, GSH depletion, and increased glucose flux through the oxidative pentose phosphate pathway (PPP) in erythrocytes. Incubation of erythrocytes with VC induced hemolysis, which was exacerbated in erythrocytes from glucose-6-phosphate dehydrogenase (G6PD) patients and rescued by antioxidants. Thus, erythrocytes protect cancer cells from VC-induced oxidative stress and undergo hemolysis in vitro, despite activation of the PPP. These results have implications on the use of high dose VC in ongoing clinical trials and highlight the importance of the PPP in the response to oxidative stress.

Influence of Gibberellic Acid and Blossom Removal on Fruit Quality of Strawberry (Fragaria x ananassaDuch.) CV. Belrubi

A study were carried out to investigate the effect of gibberellic acid (GA3) and blossom removal on fruit quality of strawberry cv. belrubi under subtropical region. Various quality parameters were monitored with the application of three concentrations of gibberellic acid (GA3) 50 ppm, 100 ppm and 150 ppm and two levels of blossom removal partial and without deblossoming. Results of experimental showed that the highest juice content of fruits (86.70/86.46%), TSS (7.56/7.43°Brix), sugar content (4.33/4.26%), pH of fruit (3.87/3.86) were recorded in lower concentration of gibberellic acid 50 ppm treated plants with partial deblossoming during both the years of experimentations (2003–04 and 2004–05). However, the highest vitamin-C (63.75/63.66 mg/100g) was obtained with treatment combination 100 ppm GA3 with partial deblossoming. In addition, the highest acidity of fruit (0.77 and 0.79%) was registered in control (water spray without deblossoming) during both the years. From this study, it can be concluded that spraying of 50 ppm GA3 with partial blossom removal treated plants showed improve of fruit quality.

Correlation between cultivation methods and quality in some vegetable species

Quality parameters of 5 table root varieties were tested on 3 sowing dates with different cultivation methods: open field on 15 April and 9 July 2010 and under plastic tents on 19 August. The highest red pigment content (betanin) was measured in the varieties Akela and Mona Lisa (~ 80 mg 100 g-1) of the second (July) crop. This crop is in general use in Hungary. In comparison, in the late sown varieties (August, under plastics) a further pigment increase (10–20 mg 100 g-1) was observed in the same varieties as related to the earlier sowing dates. Yellow pigments (vulgaxanthins) showed similar trends. Roots of the late sowing date (with harvest in December) contained the highest vulgaxanthin values (103.3–124.18 mg kg-1).Varieties reacted differently to temperature changes during the production period and thus to sugar accumulation. In the second crop (July) higher water soluble solids content was measured on the average of varieties (10.12%) in comparison to the April sowing (7.76%). Beetroots of the spring sowing are recommended for fresh market while the second (July) crop with autumn harvest can satisfy industry requirements. Late sowing under unheated plastic tents supply us with fresh beetroot in late autumn and early winter and prolong the usability of plastic tents. Six lettuce species/subspecies were tested in the open field and under plastic tents in 3 repetitions for nitrate nitrogen, vitamin-C, polyphenol (gallus acid equivalent – mg GAE 100 g-1) and mineral element (Ca, K, Mg, Na) contents. Our measurements showed lower nitrate nitrogen values under plastic than in the open field (89.10± 8.13 and 127.06±14.29 mg kg-1) on the average of genotypes. Lettuce grown in the field had higher vitamin-C content (1.4 mg%) which is nearly 50% more than in plants under plastic. The highest polyphenol content was found in samples from the field with a conspicuous value of 804.17±56.47 mg GAE 100 g-1 in Piros cikória. Samples grown under plastic were richer in mineral elements (Ca, K, Mg, Na) which can be explained by the higher nutrient content of the soil. In this environment superior Mg content was observed in Edivia (4616.33±311.21 mg kg-1). &#x0D; Besides the well- known headed lettuce, Piros cikória (Red chicory),the red leaved Lollo Rossa and Tölgylevel (Oak leaf lettuce) should bementioned which well deserve further testing in order to supply us with nourishing, healthy food.

Variation of physical and chemical characters within an elite sea buckthorn ( Hippophae rhamnoides L.) breeding population

Physicochemical characteristics of 44 elite sea buckthorn bushes were determined over 2 years. The bushes can be divided into five groups on the basis of their origins. Significant group differences were detected among most studied traits. Finnish origins (subsp. rhamnoides) were characterized by low vitamin C (VC) concentration, low total sugar (TS) concentration and high titratable acidity (TA), while Chinese origins (subsp. sinensis) showed high VC, TS and TA. Progenies from crosses between Finnish and Danish individuals showed no significant difference from their parents for the traits concerned. Hybrids between Chinese (subsp. turkestanica) and Finnish individuals were intermediate. However, hybrids between Siberian and Finnish individuals had a relatively high sugar:acid ratio (SAR), which is a desirable property for fresh fruit production. Large fluctuations in physicochemical characteristics between the two years show that the results of one year are not sufficient to reveal the phenotypic potential of a particular genotype. However, strong rank-order correlations for VC, TA, pH, TS, SAR and berry shape between the two years suggest that one can compare different genotypes on the basis of 1 year’s data. The negative correlation between seed weight and TS suggests that seed weight could usefully and cheaply predict sugar concentration of sea buckthorn berries in a preliminary screening. Climatic conditions and variable periods between ripening and harvesting appear to have considerable effects on the studied traits.

EFFECT OF LOCATION ON VITAMIN C CONTENT OF SELECTED BELL PEPPER CULTIVARS

Vitamin C (VC) levels (mg/l00 g FW) were determined in 10 varieties of colored bell pepper grown under different field conditions. VC was determined by the microfluorometric method. `Orobelle' (169 mg), `King Arthur' (143 mg), `Valencia' (141 mg), and `Chocolate Bell' (134 mg) had significantly higher VC levels than `Dove' (109 mg), `Ivory' (106 mg), `Blue Jay' (93 mg), `Canary' (90 mg), and `Black Bird' (65 mg). The largest variability (53 mg) in VC levels were observed for varieties that had the highest VC content. Mean VC levels were 143a, 143a, 141a, 136a, 108ab, 93bc, and 63c for the yellow, red, orange, brown, white, purple, and black colors, respectively. Since the Recommended Daily Allowance (RDA) for VC is 60 mg per day, these results suggested that a 100-g serving of fresh bell pepper or less would supply 100% RDA of VC. Therefore, after selecting a color, growers still have the freedom to grow a variety that performs well in their area to produce peppers of high VC contents.

The common guava—a neglected fruit with a promising future

This tropical American fruit, cultivated in Florida and elsewhere around the world, was used, because of its high vitamin-C content, to fortify military food rations in World War II.