Predominant Organic Acid Research Articles

Bioleaching of heavy metals from preservative-treated wood using Aspergillus tubingensis

Abstract Although fungal bioleaching with Aspergillus niger has been investigated to remove metal from treated wood wastes, toxicological concerns limit the practical use of the species, necessitating the search for non-toxic species with comparable or greater metal removal efficiency. The removal of metals from wood treated with chromated copper arsenate (CCA) and copper amine-based preservatives was investigated using the non-ochratoxigenic mold Aspergillus tubingensis in comparison to A. niger via bioleaching. Metals were bioleached for 10 days by immersing treated wood sawdust in fungal culture filtrates. Culture filtrates were prepared by growing fungi in malt extract (ME) and sucrose media and then filtering the fungal biomass. Oxalic acid and citric acid were the predominant organic acids in A. tubingensis culture filtrate in ME and sucrose media, respectively. Citric acid present in sucrose media was found to be a more effective leaching agent for metals from preservative-treated wood. Citric acid produced by A. tubingensis and A. niger in sucrose media removed nearly 95% of copper, 80%–85% of chromium, and arsenic from CCA-treated wood, and 80%–90% of copper from wood treated with copper amine-based preservatives. As a result of its non-toxigenic characteristics and high metal removal efficiency, A. tubingensis may be a useful fungus for bioleaching metal components from inorganic preservative-treated wood.

Tree age and maturity stage affect reducing sugars, organic acids and minerals in Ziziphus jujuba Mill. cv. Huping fruits

Ziziphus jujuba Mill. is a fruit native to China, and widely distributed in the world for its nutritional value. In this study, Jujube Huping fruits were collected from tree with ages (5, 13, 30, 100-years old) at two different ripening stages. The results showed that the contents of reducing sugars increased with tree age except for 5 years old tree. Citric and malic acids were the predominant organic acids with the highest contents in the green stage of 100-year-old trees (3500 mg/100 g FW) and the red stage of 13-year-old trees (4290 mg/100 g FW), respectively. There was no specific pattern for minerals affected by the tree ages. Ca (156–397 mg/kg DW), Al (144–156 mg/kg DW), Mg (512–680 mg/kg DW) and K (7105–4617 mg/kg DW) were the main minerals in fruits. Based on Hierarchical cluster analysis and principal component analysis, the eight samples were classified into four groups: Cluster 1 (SR-5, SR-100, SG-5, and SG-13), Cluster 2 (SG-30), Cluster 3 (SR-13, SR-30), and Cluster 4 (SG-100). The study showed how the age of jujube trees affected the levels of nutrients in jujube fruits, as well as provided insights on how to grow and cultivate jujube trees of various ages.

Metabolomic and transcriptomic analyses reveal the mechanism of sweet-acidic taste formation during pineapple fruit development.

Pineapple (Ananas comosus L.) is one of the most valuable subtropical fruit crop in the world. The sweet-acidic taste of the pineapple fruits is a major contributor to the characteristic of fruit quality, but its formation mechanism remains elusive. Here, targeted metabolomic and transcriptomic analyses were performed during the fruit developmental stages in two pineapple cultivars (“Comte de Paris” and “MD-2”) to gain a global view of the metabolism and transport pathways involved in sugar and organic acid accumulation. Assessment of the levels of different sugar and acid components during fruit development revealed that the predominant sugar and organic acid in mature fruits of both cultivars was sucrose and citric acid, respectively. Weighted gene coexpression network analysis of metabolic phenotypes and gene expression profiling enabled the identification of 21 genes associated with sucrose accumulation and 19 genes associated with citric acid accumulation. The coordinated interaction of the 21 genes correlated with sucrose irreversible hydrolysis, resynthesis, and transport could be responsible for sucrose accumulation in pineapple fruit. In addition, citric acid accumulation might be controlled by the coordinated interaction of the pyruvate-to-acetyl-CoA-to-citrate pathway, gamma-aminobutyric acid pathway, and tonoplast proton pumps in pineapple. These results provide deep insights into the metabolic regulation of sweetness and acidity in pineapple.

Diversity of Phytochemical and Antioxidant Characteristics of Black Mulberry (Morus nigra L.) Fruits from Turkey.

Black mulberry (Morus nigra L.) fruits are known due to their delicious, sweet and slightly acid flavor and high anthocyanin content. In the present study, the diversity of phytochemical, sensory, and antioxidant characteristics of the fruits of 20 black mulberry genotypes, from the Artvin region of Turkey, were evaluated. As important phytochemical assessments in fruits, we chromatographically (HPLC/DAD) determined glucose (7.22 to 11.10 g/100 g fresh weight (fw)) and fructose content (6.32 and 9.94 g/100 g fw), as well as predominant organic acid in black mulberry genotypes fruits—malic acid (6.02–11.44 g/100 g fw), followed by citric acid. Titrative determination was used for ascorbic acid, finding contents of 17.41–28.33 mg/100 g fw. There was found a great diversity of sensory (taste, juiciness, and aroma) characteristics, indicating a richness of the fruit germplasm. Antioxidant parameters, such as total phenolic (TP) and anthocyanin (TA) content, were assessed spectrometrically; antioxidant activity (AA) was assessed by DPPH and FRAP assays; individual flavonoids and phenolic acids were determined chromatographically (HPLC/DAD). Antioxidant characteristics of the fruits, defined by TP and TA content, ranged from 1951 to 2733 μg GAE/g fw and 508–712 μg C3GE/g fw, respectively. The most abundant compounds of flavonoids and phenolic acids groups were determined to be rutin (47.10–97.20 mg/100 g fw) and chlorogenic acid (51.3–90.8 mg/100 g fw). AA results, measured by the DPPH method as EC50 value, ranged between 16.10 and 25.45 μg/mL; a FRAP assay revealed values of AA between 9.80 and 13.22 μmol TE/g fw. Significant differences in phytochemical and antioxidant qualities were observed among the analyzed M. nigra genotypes. Regarding the best values of phytochemical and antioxidant characteristics, three genotypes of M. nigra were selected to be recommended for fruit production. The results thus highlight the potential for the exploitation of local black mulberry genotypes through crop selection and breeding program.

PbPH5, an H+ P-ATPase on the tonoplast, is related to malic acid accumulation in pear fruit

Organic acid content is one of the most important factors influencing fruit flavors. The predominant organic acid in most pear cultivars is malic acid, but the mechanism controlling its accumulation remains unclear. In this study, by comparing gene expression levels and organic acid contents, we found that the expression of PbPH5, which encodes a P3A-ATPase, is highly correlated with malic acid accumulation in four different pear species, with correlation coefficients of 0.932**, 0.656*, 0.900**, and 0.518* (*, P<0.05; **, P<0.01) for Pyrus bretschneideri Rehd., P. communis Linn., P. pyrifolia Nakai., and P. ussuriensis Maxim., respectively. Moreover, the overexpression of PbPH5 in pear significantly increased the malic acid content. In contrast, silencing PbPH5 via RNA interference significantly decreased both its transcript level and the pear fruit malic acid content. A subcellular localization analysis indicated that PbPH5 is located in the tonoplast. Additionally, a phylogenetic analysis indicated that PbPH5 is a PH5 homolog gene that is clustered with the Petunia hybrida, Malus domestica, and Citrus reticulata genes. Considered together, these findings suggest that PbPH5 is a functionally conserved gene. Furthermore, the accumulation of malic acid in pear fruit is at least partly related to changes in the PbPH5 transcription levels.

Analysis of Free Sugars, Organic Acids, and Fatty Acids of Wood Apple (Limonia acidissima L.) Fruit Pulp

Wood apple (Limonia acidissima L.) is an underutilized, fruit-yielding tree that is native to India and Sri Lanka. Wood apple trees are also cultivated in India, Sri Lanka, Bangladesh, Myanmar, Thailand, Malaysia, Vietnam, Kampuchea, Laos, and Indonesia for delicious fruits and medicinal purposes. The major objective of the present work was the analysis of the nutritional status of wood apple fruit pulp.The fruits are rich in total carbohydrates (24.74 ± 0.19%), total proteins (9.30 ± 0.16%), oil (0.99 ± 0.01%), fiber (3.32 ± 0.02%), and ash (2.73 ± 0.12%). Further analysis and quantification of free sugars, organic acids, and fatty acid methyl esters were carried out by using high-performance liquid chromatography (HPLC) and gas chromatographic (GC) methods. In total, five sugars and nine organic acids were detected and quantified. The predominant sugars were fructose (16.40 ± 0.23%) and glucose (14.23 ± 0.10%), whereas the predominant organic acids were D-tartaric (4.01 ± 0.03%), ascorbic (4.51 ± 0.05%), and citric acid (4.27 ± 0.04%). The oil content of fruit pulp was 0.99 ± 0.01% and GC-MS analysis revealed that, it comprise of 16 fatty acid methyl esters. The percentage of saturated fatty acids were 32.17 ± 0.35%, that includes palmitic (18.52 ± 0.12%) and stearic acids (9.02 ± 0.08%), whereas, the unsaturated fatty acids were 51.98 ± 0.94%, including oleic acid (23.89 ± 0.06%), α-linolenic acid (16.55 ± 0.26%), linoleic acid (10.02 ± 0.43%), and vaccenic acid (1.78 ± 0.23%).

Unraveling the malate biosynthesis during development of Torreya grandis nuts

Torreya grandis is a characteristic rare economic tree species in subtropical mountainous areas. The kernels of T. grandis have rich content of organic acids, and malate is the predominant organic acid in T. grandis kernels. However, the contents, biosynthesis/metabolism pathway and transcriptional regulation of malate in developing T. grandis kernels remain completely unknown. Here, the organic acid composition in developing T. grandis kernels was first analyzed. The results showed that the content of malate was increased during the maturation T. grandis kernels. A malate synthase (TgMLS) gene might be involved in the accumulation of malate based on transcriptome data, gene expression and enzyme activity analysis. Transient expression of TgMLS in tobacco resulted in the high malate synthase activity and malate content. Furthermore, a basic helix-loop-helix transcription factor (bHLH), TgbHLH87 was identified to positively regulate the TgMLS expression via directly binding the TgMLS promoter. Our finding contributes to mechanism underlying malate accumulation in T. grandis kernels.

Quality Characteristics and Inhibitory Xanthine Oxidase Potential of 21 Sour Cherry (Prunus Cerasus L.) Varieties Cultivated in China.

This study aims to analyze the physicochemical characteristics and activities of 21 sour cherry cultivars in China. The evaluated accessions differ in several quality traits including weight, moisture, color, total soluble solids, and total acids. Glucose and malic acid were the predominant individual sugar and organic acid in all accessions. The potassium (K) and iron (Fe) were of the highest contents in Érid jubileum (453.887 mg/100 g FW) and Meili (2.988 mg/100 g FW), respectively. The contents of total phenolics (TP) were from 9.309 to 24.118 mg GAE/g DW, and total flavonoids (TF) were 8.935–27.198 mg RE/g DW, which were highly positively correlated (r = 0.892, p < 0.001). M-15, Érdi fubileum, and Érid jubileum showed the highest inhibitory effects on xanthine oxidase, and the IC50 inhibitory were 2.619, 3.117, and 3.940 mg/ml, respectively. This work evaluated the quality and nutritional characteristics of 21 sour cherry cultivars grown in China and explored their potential as an innovative food ingredient for hyperuricemia by evaluating the inhibitory effects of xanthine oxidase. And these results provide valuable data and new ideas for the future sour cherry breeding program as well as a processing guide.

Assessment of Morphological Traits, Nutritional and Nutraceutical Composition in Fruits of 18 Apricot cv. Sekerpare Clones

Apricot (Prunus armeniaca L.) is one of the most important members of Prunus and its trees bears delicious and nutritious fruits during summer months in the temperate zones in the world. Apricot cultivars are propagated asexually which consists of clones. Information on inter-clonal variations in apricot cultivars can assist us in the selection of better clones from commercial cultivars. We aimed to determine morphological traits (fruit weight, seed weight, kernel weight, flesh/seed ratio, shape index, fruit firmness, color index), nutritional (sugars and organic acids) and nutraceutical (total phenolic, total flavonoids, total carotenoid and antioxidant activity) composition of 18 clones of Sekerpare apricot cultivar grown together in Kagizman district in eastern Turkey. Results showed significant differences among clones concerning most of the morphological traits, nutritional and nutraceutical compositions. Fruit weight, flesh/seed ratio and fruit firmness of clones were in range of 23.14–27.11 g, 11.21–13.14 and 3.88–5.11 kg/cm2, respectively. Fruit shape index was slightly similar among all clones which was between 0.95 and 1.03. Citric acid and sucrose were found to be the predominant organic acid and sugar among clones which varied from 728 to 915 mg/100 g and 7.11 to 9.94 g/100 g, respectively. The clone ‘KS2’ exhibited the highest level of total phenol (67.1 mg gallic acid equivalent per 100 g) and antioxidant activity (2.16 μmol trolox equivalent per g). The study confirmed the diversity among Sekerpare clones and effectiveness of combining morphological, nutritional and nutraceutical analyses in assessment of Şekerpare clones and its use for future pre-breeding programs.

The Effect of Organic, Inorganic Fertilizers and Their Combinations on Fruit Quality Parameters in Strawberry

Strawberry (Fragaria × ananassa Duch.) is widely grown and highly appreciated by consumers around the world for its delicious, soft, and highly nutritious fruits. Turkey is one of the most important strawberry producers in the world. Strawberry cultivation in Turkey typically involves the use of chemical fertilizers and more recently organic and organic + chemical fertilizers have been started to use in commercial production to produce healthier fruits. Therefore, in this study, we investigated the effect of organic, chemical, and organic + chemical fertilizer treatments in strawberry (cvs. ‘Albion’, ‘San Andreas’ and ‘Monterey’) fruit quality parameters including fruit color (L*, a*, b*, C and h°) parameters, soluble solids content, total acidity, fruit firmness, vitamin C, specific sugars and organic acids. Results showed that in particular fruit color parameters, soluble solid content (SSC), total acidity, fruit firmness, and vitamin C (L-Ascorbic acid) in fruits of three strawberry cultivars were significantly affected by different fertilizer applications (p &lt; 0.05). Compared with conventional chemical fertilizer treatment, the organic fertilizer treatment produced fruit with significantly higher contents of SSC and glucose but decreased fruit firmness and vitamin C. Organic fertilizer also gave more intense colored strawberry fruits with high Chroma values (47,948 in organic fertilizer application and 39,644 and 39,931 in organic + chemical fertilizer and chemical fertilizer, respectively). Citric acid was identified to be the predominant organic acid in strawberry fruits but treatments were found insignificant on citric acid content.

Chemical and nutritional characteristics of crackers substituted with Cucurbita pepo L. seed flour

The aim of the study was determined the suitability of Cucurbita pepo L. (pumpkin) seed flour (PSF) supplement, which is limited for use in the food industry, to increase some chemical and functional properties of crackers. PSFs were used to replace wheat flour in cracker formulation at the levels of 5, 10, 20 and 30%. Particularly, the total dietary fiber, protein and ash content of crackers with PSF increased. The highest increase in mineral contents of crackers were determined in P&gt; K&gt; Mg&gt; Ca&gt; Zn&gt; Fe&gt; Cu. The predominant organic acid of crackers was tartaric acid and the dominant fatty acid was linoleic acid. Crackers prepared with Nevşehir variety PSF yielded better results than other crackers due to their nutritious properties. As a result, with the addition of PSF, a functional food product with health benefits was obtained and a contribution was made to the product range.

Changes in the Content of Organic Acids and Expression Analysis of Citric Acid Accumulation-Related Genes during Fruit Development of Yellow (Passiflora edulis f. flavicarpa) and Purple (Passiflora edulis f. edulis) Passion Fruits.

Organic acids are key components that determine the taste and flavor of fruits and play a vital role in maintaining fruit quality and nutritive value. In this study, the fruits of two cultivars of passion fruit Yellow (Passiflora edulis f. flavicarpa) and purple (Passiflora edulis f. edulis) were harvested at five different developmental stages (i.e., fruitlet, green, veraison, near-mature and mature stage) from an orchard located in subtropical region of Fujian Province, China. The contents of six organic acids were quantified using ultra-performance liquid chromatography (UPLC), activities of citric acid related enzymes were determined, and expression levels of genes involved in citric acid metabolism were measured by quantitative real-time PCR (qRT-PCR). The results revealed that citric acid was the predominant organic acid in both cultivars during fruit development. The highest citric acid contents were observed in both cultivars at green stage, which were reduced with fruit maturity. Correlation analysis showed that citrate synthase (CS), cytosolic aconitase (Cyt-ACO) and cytosolic isocitrate dehydrogenase (Cyt-IDH) may be involved in regulating citric acid biosynthesis. Meanwhile, the PeCS2, PeACO4, PeACO5 and PeIDH1 genes may play an important role in regulating the accumulation of citric acid. This study provides new insights for future elucidation of key mechanisms regulating organic acid biosynthesis in passion fruit.

Nutrient compositions and functional constituents of 12 crabapple cultivars ( Malus Mill. species): Aptitudes for fresh consumption and processing

Crabapple is a species with roles in aesthetics, ecology, and food materials. Twelve crabapple cultivars (Malus Mill. spp.) were analyzed for nutritional composition and functional constituents. Results show that amounts of ascorbic acid (202–704 mg/g) and phenolic compounds (665.96–2275.30 mg GAE/100 g) in these crabapple varieties are higher than those in some common fruits. Glucose and fructose were the most abundant sugars found in all cultivars, while the predominant organic acid in the different cultivars varied. Crabapples showed high DPPH radical scavenging activity and reducing power. Rutin was the predominant flavonoid component, while vanillic acid and chlorogenic acid were the major phenolic acids in most of the crabapples. Among the cultivars studied, Royalty, Strawberry Parfait, Sparkler, and Adams showed the highest total phenol content and flavonoid content, which have health benefits. Fresh Kelsey and Fuguhongguo were suitable for consumption. The cultivars were well-separated by principal component analysis (PCA). Novelty Impact Statement Twelve crabapple cultivars were analyzed for nutritional composition and functional constituents. Phenolic compounds (665.96–2275.30 mg GAE/100 g) in these crabapple varieties are higher than those in some common fruits. The different cultivars which had different physicochemical and antioxidant characteristics can be well-separated by principal component analysis (PCA).

Metabolite Fruit Profile Is Altered in Response to Source-Sink Imbalance and Can Be Used as an Early Predictor of Fruit Quality in Nectarine.

Peaches and nectarines [Prunus persica (L.) Batsch] are among the most exported fresh fruit from Chile to the Northern Hemisphere. Fruit acceptance by final consumers is defined by quality parameters such as the size, weight, taste, aroma, color, and juiciness of the fruit. In peaches and nectarines, the balance between soluble sugars present in the mesocarp and the predominant organic acids determines the taste. Biomass production and metabolite accumulation by fruits occur during the different developmental stages and depend on photosynthesis and carbon export by source leaves. Carbon supply to fruit can be potentiated through the field practice of thinning (removal of flowers and young fruit), leading to a change in the source–sink balance favoring fruit development. Thinning leads to fruit with increased size, but it is not known how this practice could influence fruit quality in terms of individual metabolite composition. In this work, we analyzed soluble metabolite profiles of nectarine fruit cv “Magique” at different developmental stages and from trees subjected to different thinning treatments. Mesocarp metabolites were analyzed throughout fruit development until harvest during two consecutive harvest seasons. Major polar compounds such as soluble sugars, amino acids, organic acids, and some secondary metabolites were measured by quantitative 1H-NMR profiling in the first season and GC-MS profiling in the second season. In addition, harvest and ripening quality parameters such as fruit weight, firmness, and acidity were determined. Our results indicated that thinning (i.e., source–sink imbalance) mainly affects fruit metabolic composition at early developmental stages. Metabolomic data revealed that sugar, organic acid, and phenylpropanoid pathway intermediates at early stages of development can be used to segregate fruits impacted by the change in source–sink balance. In conclusion, we suggest that the metabolite profile at early stages of development could be a metabolic predictor of final fruit quality in nectarines.

Primary, Secondary Metabolites and Molecular Characterization of Hawthorn (Crataegus spp.) Genotypes

In this study, the molecular, biochemical and agro-morphological characterization of genotypes belonging to hawthorn species collected from Bolu province of Turkey was performed. Inter-priming binding sites (iPBS) markers based on retrotransposons were used for the first time in the molecular properties of hawthorn genotypes in the world. The marker system provided very useful information for revealing the genetic variation of the genotypes. Six iPBS markers amplified 68 fragments, of which 65 were polymorphic (95.59%) with an average of 10.83 polymorphic bands per primer. The polymorphism and resolving power per primers ranged from 0.12 to 0.42 and from 0.78 to 8.11 with the average being 0.32 and 5.95, respectively. Pomological properties of Crataegus tanacetifolia, such as fruit pomology and core weight were determined to higher than those of Crataegus monogyna. Citric acid was determined as the most predominant organic acid, followed by malic and succinic acid in the genotypes of both species. The highest citric acid content (26.745 mg 100 g−1) was noted for 14BL09 genotype. The vit. C content was recorded ranging from 2.681 to 9.621 mg 100 g−1. Catechin, chlorogenic, caffeic and rutin contents were varied between 4.140–51.393 mg, 2.254–42.361 mg, 0.624–4.407 mg, and 1.241–10.029 mg per 100 g of fruits, respectively. As a result, it has been determined that twenty-five genotypes belonging to different hawthorn species are important genetic resources to be evaluated in horticultural breeding studies in terms of their physical and biochemical contents.

Profiles of Sugar and Organic Acid of Fruit Juices: A Comparative Study and Implication for Authentication

A comparison of sugar and organic acid profiles among different fruit juices (including apple, pear, peach, grape, sweet cherry, strawberry, and blueberry with various varieties) was performed to assess the possibility for authentication coupled with chemometrics. It was found that the distribution of each sugar and organic acid in juices showed some specific characteristics related to fruit species, despite the fact that great differences in the content existed among different varieties. Sucrose was the most abundant sugar in peach juice, accounting for 58.26–77.11% of the total sugar content. However, in grape, blueberry, and sweet cherry juice, glucose and fructose were the predominant sugars. Pear juice contained the highest level of sorbitol, which contributed to 15.02–43.07% of the total sugar content. Tartaric acid was detected only in grape juice among the seven species of fruit juice, with a proportion of 57.95–89.68% in the total acid content. Malic acid was the predominant organic acid in apple and sweet cherry juice, accounting for 69.92–88.30% and 97.51–98.73% of the total acid content of each species. Citric acid was the predominant organic acid in strawberry and blueberry juice, which contributed to 62.39–83.73% and 73.36–89.56% of the total acid content of each species. With the aid of principal component analysis and linear discriminant analysis (LDA), the juice samples could be successfully classified according to fruit species by using the sugar and/or organic acid composition as analytical data. Combination of sugar and organic acid composition gave the best differentiation of these seven species of juices, with a 100% correct classification rate for both the original and the cross-validation method in LDA. Adding malic/citric into the dataset of the organic acid content may also improve the differentiation effect. Furthermore, the adulteration of sweet cherry juice, blueberry juice, raspberry juice, and grape juice with apple juice, pear juice, or peach juice could also be distinguished from their corresponding pure juices based on sugar and organic acid composition by LDA.

Total titratable acidity and organic acids of wines produced from cactus pear (Opuntia-ficus-indica) fruit and Lantana camara (L. Camara) fruit blended fermentation process employed response surface optimization.

Fruits and fermentation methods are important sources of organic acids that determine organoleptic properties, microbiological and biochemical stability of fruit wines. This study is aimed at investigating total titrable acidity and organic acids of fruit wines produced by response surface optimization of cactus pear and Lantana camara fruits blend and cactus pear fruit alone. The predictive mathematical model of the blended fruit wine is well fitted (R 2 = 0.9618 and absolute average deviation (AAD) = 2.06%). The optimum values of fermentation temperature, inoculum concentration, and Lantana camara fruitjuice concentration to produce predictive total titrable acidity of 0.8% (w/v citric acid) were 24°C, 10% (v/v), and 10.7% (v/v), respectively. The blended fruit wine was with lower total titrable acidity (w/v citric acid) of 0.83 ± 0.058% compared to wine produced from cactus pear fruit alone 1.06 ± 0.27%. The high performance liquid chromatography (HPLC) analysis of both produced wines revealed the difference in concentration of citric (±3.35 mg/ml), L‐tartaric (± 3.71 mg/ml), and L‐ascorbic acid (± 0.07 mg/ml). Citric acid was predominant organic acid in both fruit wines, and its content in the cactus pear is 7.09 ± 0.07 mg/ml and blended fruit wine 4.74 ± 0.07 mg/ml.

Changes in quality attributes during production steps and frozen-storage of pomegranate juice concentrate

In this study, changes in critical quality attributes of pomegranate juice that was evaluated in juice processing line for obtaining clarified pomegranate juice concentrate were investigated. To achieve that juice samples collected from each production steps throughout juice processing line were analyzed. Moreover, the obtained pomegranate juice concentrate was kept at frozen conditions and monitored quality changings (color and anthocyanin compounds) for six months. The turbidity of the samples showed a significant decrease especially after filtration processes. The color parameters decreased remarkably after ultra-filtration. In pomegranate juice, six anthocyanin compounds were detected and the most abundant one was cyanidin-3,5-diglucoside (117 mg/L). The decrease of TMAC in pomegranate juice was 27.8 % at the end of processing line, compared to fresh juice. Moreover, as colorless phenolics, fourteen compounds were identified and the most abundant one was ellagic acid (122 mg/L) and followed by gallic acid (108 mg/L) in fresh juice. Ellagic acid and gallic acid were respectively decreased by 25.7 % and 41.0 % at the end of processing line. The predominant organic acid and mineral were citric acid (17.4–25.5 g/L) and K (2648−3005 mg/L) in all production stages, respectively. The results showed that the main phenolic compounds in pomegranate juice affected dramatically during processing stages, especially after clarification and filtration processes. However, high stability for anthocyanin compounds was determined during frozen storage of the juice concentrate.

Juá fruit (Ziziphus joazeiro) from Caatinga: A source of dietary fiber and bioaccessible flavanols.

Fruits from Ziziphus joazeiro from Mata Paraibana (MP), Borborema (BB), Agreste (AG) and Sertão Paraibano (SP) were assessed to determine their morphological characteristics, nutritional composition, content and bioaccessibility of phenolic compounds and antioxidant activity. In general, juá fruits presented ovoid shape, high moisture (65.33-72.53%), low acidity, with succinic acid being the predominant organic acid, and high dietary fiber content (8.98-10.81%), mostly insoluble fibers (5.72-8.02%). Fruits from MP presented the highest amounts of free phenolic compounds (24.27mg/100g) and the highest antioxidant activity in the DPPH, FRAP and ORAC assays. In MP fruits, epigallocatechin gallate (12.04mg/100g) was the major compound, while in fruits from other states, phenolic compounds were the major compounds. The bioaccessibility of catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, procyanidin and syringic acid varied among fruits from different regions. Fruits from SP presented the highest phenolic content in the bioaccessible fraction and highest antioxidant activity in all assays. The findings of this study indicate that juá is a non-acidic fruit with highest moisture, source of fiber, majority insoluble fibers and bioaccessible flavanols.

Phytochemical composition and antioxidant activity of 63 Balkan pepper (Capsicum annuum L.) accessions

In our study, we used the rich biodiversity of peppers in the Balkan region and characterized 63 pepper accessions from five cultivar types (Pungent; Sweet; Pumpkin; Kapia; For powder), in view of their phytochemical composition and antioxidant activity. The obtained results showed high variation in the compositional profiles between studied cultivar groups, as well within individual groups. Based on fresh weight (FW), the most abundant sugar in the studied accessions was glucose (0.36–3.79%), followed by fructose (0.16–2.98%). The accessions from “For powder” group were the richest source of uronic acids—0.77%, followed by accessions from “Pungent” group—0.64%. In four of the five groups, citric acid was the predominant organic acid, whereas only in the “Sweet” group, malic acid was the major representative of organic acid. The highest amount of ascorbic acid (Vitamin C) was found in a genotype CAPS-7, which is in the group of “Pungent” accessions. The polyphenol content varied in a broad range from 42 mg/100 g FW to 266 mg/100 g FW. The differences in the flavonoid content were even more significant reaching 60-fold difference—from 1.0 mg/100 g FW to 64.3 mg/100 g FW. The accessions from the “For powder” group were leaders in regards to their total polyphenol and total flavonoid contents, as well as for their antioxidant activity, measured by ORAC and HORAC assays. This variation in fruit composition might be manipulated via plant breeding to create new pepper varieties with improved nutritional value of their fruits.