Rootstock effects on bitter pit incidence in 'Honeycrisp' apples are associated with changes in fruit's cell wall chemical properties.

Bitter pit (BP) is a physiological disorder of apples that often appears during or after cold storage. Despite being defined as a calcium deficiency disorder, BP is a complex process that is not only affected by the total Ca2+ content in the fruit but also by the proper cellular Ca2+ homeostasis and partitioning. Early investigations have also suggested that rootstocks could affect BP development and severity. In the present study, rootstock effects on BP development were assessed on 'Honeycrisp' trees that were grafted on 14 different rootstocks (B.10, G.11, G.202, G.214, G.30, G.41, G.935, G.969, M.26 EMLA, M.9, V.1, V.5, V.6, and V.7). We evaluated BP incidence at harvest, and three months after cold storage for four, and three growing seasons, respectively. BP incidence was significantly reduced in 'Honeycrisp' trees on B.10 compared to other rootstocks, whereas trees on V.6 showed the highest percentage of BP at harvest and after cold storage. 'Honeycrisp' apples were collected from three different rootstocks (B.10, G.41, and V.6) two months after cold storage and evaluated for mineral nutrient composition, Ca2+ homeostasis, and cell wall properties, e.g., pectin content, pectin de-esterification rate and pectin methylesterase (PME) activity. Water-soluble and insoluble pectin content was markedly higher in fruits from B.10 than in G.41 and V.6. We also observed increased PME enzyme activity and a greater degree of water-insoluble pectin de-esterification in 'Honeycrisp' apples from V.6 compared to those from B.10. A significantly higher Ca2+ was found in the fruits from B.10 than G.41 and V.6. Higher Ca2+ and lower Mg2+ levels were also observed in the cell wall and water-insoluble pectin fractions of the fruits from B.10 compared to G.41 and V.6. However, the ratio of cell wall-bound Ca2+ to total Ca2+ was lower in B.10 compared to G.41 and V.6. Together, our results indicate that the tolerance of B.10 to BP could be attributed to a reduced PME activity and lower pectin de-esterification level, which in turn reduced the amount of Ca2+ cross-linked with pectin, and probably increased the apoplastic free calcium concentrations that is essential for maintaining cell membrane integrity and reducing BP development.

Diversity in blueberry genotypes and developmental stages enables discrepancy in the bioactive compounds, metabolites, and cytotoxicity.

Eight blueberry cultivars at three developmental stages were investigated for metabolite profiling, antioxidant, and anticancer activities. Cultivars- and developmental stages-variations were determined in total phenolic, flavonoid, DPPH, and FRAP antioxidant assays. The anticancer capacity was equal against A549, HepG2, and Caco-2 cancer cells, whereas the inhibition rate was dose-, incubation period-, cultivar-, and developmental stages-dependent. The untargeted metabolite profiling by UPLC-TOF-MS analysis of two contrast cultivars, 'Vernon' and 'Star', throughout the developmental stages revealed 328 metabolites; the majority of them were amino acids, organic acids, and flavonoids. The multivariate statistical analysis identified five metabolites, including quinic acid, methyl succinic acid, chlorogenic acid, oxoadipic acid, and malic acid, with positively higher correlations with all anticancer activities. This comprehensive database of blueberry metabolites along with anticancer activities could be targeted as natural anticancer potentials. This study would be of great value for food, nutraceutical, and pharmaceutical industries as well as plant biotechnologists.

Removal of astringency in persimmon fruits (Diospyros kaki) subjected to different freezing temperature treatments.

The effects of two different freezing temperatures (- 20 °C and - 80 °C) on the astringency trait of persimmon fruits during 15 to 60 days of storage were investigated. The levels of soluble and insoluble tannins, proanthocyanidins and other physicochemical characteristics were evaluated. Storage at - 20 °C and - 80 °C temperatures up to 60 days has been found to be an effective method to remove astringency of persimmon fruits. Proanthocyanidin concentration was negligible at both temperatures during storage. Total soluble solid contents were decreased as 3.34 from 4.59 (mg/g DW) whereas, insoluble tannin contents were increased as 20.30 from 16.45 (mg/g DW) by freezing temperatures treatment during storage. Comparatively, higher soluble tannin content 11.68 (mg/g DW) and lower insoluble tannin content 10.02 (mg/g DW) was observed in control (day 0). Therefore, the astringency of persimmon fruits incubated at - 20 °C and - 80 °C was markedly reduced and after 15 up to 60 days of storage, the astringent taste virtually disappeared. The proanthocyanidin contents were decreased as 0.02 from 0.52 (mg/g DW) at - 20 °C storage and 0.17 from 0.47 (mg/g DW) at - 80 °C storage, in comparison with the control 2.65 (mg/g DW). The moreover, along with the removal of astringency, other physicochemical parameters including color, pH, moisture content, total soluble solid, and sensory attributes were also conserved on freezing at both the temperatures. These findings suggest that freezing temperature treatments aid the removal of astringency from persimmon fruits which could be used in different food preparations or as supplements.

Untargeted Metabolomics and Antioxidant Capacities of Muscadine Grape Genotypes during Berry Development.

Three muscadine grape genotypes (Muscadinia rotundifolia (Michx.) Small) were evaluated for their metabolite profiling and antioxidant activities at different berry developmental stages. A total of 329 metabolites were identified using UPLC-TOF-MS analysis (Ultimate 3000LC combined with Q Exactive MS and screened with ESI-MS) in muscadine genotypes throughout different developmental stages. Untargeted metabolomics study revealed the dominant chemical groups as amino acids, organic acids, sugars, and phenolics. Principal component analysis indicated that developmental stages rather than genotypes could explain the variations among the metabolic profiles of muscadine berries. For instance, catechin, epicatechin-3-gallate, and gallic acid were more accumulated in ripening seeds (RIP-S). However, tartaric acid and malonic acid were more abundant during the fruit-set (FS) stage, and malic acid was more abundant in the veraison (V) stage. The variable importance in the projection (VIP > 0.5) in partial least-squares-discriminant analysis described 27 biomarker compounds, representing the muscadine berry metabolome profiles. A heatmap of Pearson's correlation analysis between the 27 biomarker compounds and antioxidant activities was able to identify nine antioxidant determinants; among them, gallic acid, 4-acetamidobutanoic acid, trehalose, catechine, and epicatechin-3-gallate displayed the highest correlations with different types of antioxidant activities. For instance, DPPH and FRAP conferred a similar antioxidant activity pattern and were highly correlated with gallic acid and 4-acetamidobutanoic acid. This comprehensive study of the metabolomics and antioxidant activities of muscadine berries at different developmental stages is of great reference value for the plant, food, pharmaceutical, and nutraceutical sectors.

Effects of superfine grinding using ball-milling on the physical properties, chemical composition, and antioxidant properties of Quercus salicina (Blume) leaf powders.

BACKGROUND: Quercus salicina (Blume) leaves are traditionally used as folk medicine in some Asian countries. The aim of this study was to evaluate the effects of ball milling for different periods (0, 6, 12, 18, and 24 h) on the physicochemical properties of superfine Quercus salicina (Blume) leaf (QSL) powders. RESULTS: The particle sizes, water-holding capacity, angle of repose, and redness of the superfine QSL powder decreased with increasing ball-milling times, whereas the water solubility index, bulk density, tapped density, brightness, and yellowness were found to increase. Significantly higher (P > 0.05) total phenolic and flavonoid contents, and antioxidant activities, were observed for the superfine QSL powders obtained after 24 h ball-milling time. A total of 12 phenolic compounds in free and cell-wall-bound forms were quantified in the superfine QSL powder. Free phenolics such as protocatechuic acid, caffeic acid, rutin, and p-coumaric acid were increased and all cell-wall-bound phenolics were decreased with increasing ball-milling times. The antioxidant activity of the free phenolics increased with increasing ball-milling times, and the cell-wall-bound forms decreased. CONCLUSION: Superfine grinding by ball milling for 24 h can thus be used to produce superfine QSL powder with higher free phenolic metabolite content and antioxidant activity, and improved water solubility index, color, bulk, and tapped densities. This study will be useful for the food / nutraceutical / pharmaceutical industries in the manufacturing of active food ingredients or value-added products using QSL powders. © 2020 Society of Chemical Industry.

Aqueous green tea infusion extracted by ultra-sonication method, but not by conventional method, facilitates GLUT4 membrane translocation in adipocytes which potently ameliorates high-fat diet-induced obesity.

Green tea contains bioactive compounds, such as polyphenols, responsible for its health-promoting effects, including antiobesity and antidiabetic effects. We previously reported that ultra-sonication extraction (UE) could efficiently increase the extraction yield of green tea compounds. In the present study, we found that the extract obtained using UE contained higher phenolic and flavonoid contents than that obtained using the conventional method. We therefore considered the extract as a bioactive metabolite-rich functional green tea extract (BMF-GTE), and tested its glucose-lowering effect by generating an adipocyte cell line stably expressing 7myc-GLUT4-GFP. We found that BMF-GTE treatment increased GLUT4 translocation to the plasma membrane. Moreover, BMF-GTE administration attenuated weight gain in mice fed a high-fat diet (HFD). Importantly, HFD-induced glucose tolerance was ameliorated in the mice receiving BMF-GTE. Therefore, we conclude that BMF-GTE worked against obesity and diabetes, at least partially, by enhancing GLUT4 translocation in adipocytes. PRACTICAL APPLICATIONS: As green tea is one of the most consumed beverages worldwide, its health effects have been widely tested. In our previous studies, we found that ultra-sonication extraction (UE) has the potential to increase the aqueous extraction yield of green tea compounds compared to conventional extraction techniques. In this study, we examined the biological effect of bioactive metabolite-rich functional green tea extract (BMF-GTE) obtained using UE; we observed that administering BMF-GTE lowered the body weight and increased insulin sensitivity in mice fed a high-fat diet, potentially by facilitating the membrane translocation of GLUT4 in adipocytes. Therefore, this study suggests that the extract obtained with UE had antiobesity and antidiabetic properties, indicative of a potential application of UE in maximizing the beneficial effects of green tea on human health.

Application of Exogenous dsRNAs-induced RNAi in Agriculture: Challenges and Triumphs.

In recent years, RNA interference (RNAi) machinery has widely been explored by plant biologists for its potential applications in disease management, plant development, and germplasm improvement. RNAi-based technologies have mainly been applied in the form of transgenic plant generation and host-induced-gene-silencing (HIGS). However, the approval of RNAi-based transgenic plants has always been challenging due to the proclaimed concerns surrounding their impacts on human health and the environment. Lately, exogenous applications of double-stranded RNAs (dsRNAs), short interfering RNAs (siRNAs), and hairpin RNAs (hpRNAs) has emerged as another technology that could be regarded as more eco-friendly, sustainable, and publicly acceptable than genetic transformation. Inside the plant cell, dsRNAs can undergo several steps of processing, which not only triggers RNAi machinery but may also involve transitive and systemic silencing, as well as epigenetic modifications. Therefore, along with the considerations of proper exogenous applications of dsRNAs, defining their final destination into plant cells is highly relevant. In this review, we highlighted the significance of several factors that affect dsRNA-induced gene silencing, the fate of exogenous dsRNAs in the plant cell, and the challenges surrounding production technologies, cost-effectiveness, and dsRNAs stability under open-field conditions. This review also provided insights into the potential applications of exogenous dsRNAs in plant protection and crop improvement.

A review of encapsulation of carotenoids using spray drying and freeze drying.

Carotenoids are potent antioxidants, but they are highly unstable and susceptible during processing and storage. Encapsulation technologies protect against degradation and are capable of releasing individual or combination of bioactive substances during processing as well as development of various functional food products. Moreover, encapsulating agents can be used to increase the stability of carotenoids and form a barrier between the core and wall materials. Suitable encapsulating agents, temperature, and drying methods are the most important factors for the encapsulation process. In this report, we reviewed the current status of encapsulation of carotenoids from different fruits, vegetables, spices, seaweeds, microorganisms, and synthetic sources using various types of encapsulating agents through spray drying and freeze drying. We also focused on the degradation kinetics and various factors that affect the stability and bioavailability of encapsulated carotenoids during their processing and storage.

Profiling of volatile and non-phenolic metabolites-Amino acids, organic acids, and sugars of green tea extracts obtained by different extraction techniques.

Volatile compounds and non-phenolic metabolites (amino acids, organic acids, and sugars) of aqueous green tea extracts obtained by ultrasonic extraction (UE), agitation extraction (AE), hot water extraction (HWE), and conventional extraction (CE) were determined using SPME-GC-MS and HPLC, respectively. Significantly higher (P < 0.05) yields of volatiles and non-phenolic metabolites were obtained via UE and AE than via HWE and CE. UE, AE, HWE, and CE released 212, 201, 103, and 65 volatiles, respectively. Sum total of amino acid and organic acid in extracts was 54.57, 54.35, 27.11, and 12.67 (mg/100 g), and 5.96, 6.19, 3.81, and 1.68 (mg/100 g) for UE, AE, HWE, and CE, respectively. Volatiles except nitrogen-containing compounds had higher positive correlations with l-theanine, sucrose, malic acid, and catechins yields. Findings of the current study suggest that an efficient extraction technique may significantly increase volatile and non-phenolic metabolite yields in aqueous green tea extract.

A comparative study of ultra-sonication and agitation extraction techniques on bioactive metabolites of green tea extract.

The aim of this study was to compare methods for efficient extraction of green tea metabolites. Aqueous green tea leaf powder extracts were prepared by ultra-sonication extraction (UE), agitation extraction (AE), and the conventional extraction method (control) at different temperatures (60, 70, and 80 °C) and times (5-30 min). Compared to the control, both UE and AE techniques significantly increased the yields of polyphenols (three-fold), catechins (two-fold), and flavonoids (two-fold), and resulted in higher antioxidant activity. For both techniques, highest extraction efficiency of bioactive metabolites occurred at 80 °C for 20 min. Caffeine, total free amino acid, vitamin C, and total soluble solid contents were also significantly increased using either technique compared to the control. Thus, AE and UE have similar extraction efficiencies and could be used to prepare antioxidant-rich green tea extract or green tea extract powder.

Characterization of p-Coumaric acid-induced soluble and cell wall-bound phenolic metabolites in relation to disease resistance to Xanthomonas campestris pv. campestris in Chinese cabbage.

To characterize the p-coumaric acid (pCA)-induced phenolic metabolites in relation to the disease resistance against Xanthomonas campestris pv. campestris (Xcc.), the responses of soluble- and cell wall-bound flavonoid and hydroxycinnamic acids compounds to the pretreatment of pCA or the inhibitor of the 4-coumarate-CoA ligase, 3,4-(methylenedioxy) cinnamic acid (MDCA), following Xcc inoculation were assessed, and the resulting data were interpreted with regard to susceptibility to Xcc in Chinese cabbage (Brassica rapa var. pekinensis). At 12 days post-inoculation (DPI) with Xcc, disease symptom development could be distinguished by necrotic lesions, and characterized by an enhanced lipid peroxidation. Overall, pCA acts as a positive stimulus for an accumulation of hydroxycinnamic acids and flavonoids, while MDCA acts as a negative regulator. Pretreatment with pCA resulted in an accumulation of specific hydroxycinnamic acids, pCA, ferulic acid (FA), and sinapic acid (SiA) in both soluble and cell wall-bound forms in Xcc-inoculated leaves, while MDCA pretreatment decreased accumulation in a dose-dependent manner. Two flavonoid compounds, epigallocatechin (EGC) and epigallocatechin gallate (EGCG), showed a similar response to pCA and MDCA pretreatments. These results indicate that a lower disease symptom development in pCA-pretreated leaves was associated with a higher accumulation of hydroxycinnamic acids and flavonoids, and vice-versa in MDCA- and non-pretreated (control) leaves.

Ethnomedicinal plants of the Bauri tribal community of Moulvibazar District, Bangladesh.

CONTEXT: Bangladesh reportedly has more than 100 tribal communities; however, documentation of their medicinal practices is markedly absent. AIM: The aim of the present study was to conduct an ethnomedicinal survey among the little known Bauri tribe of Bangladesh, whose tribal medicinal practices are yet to be documented. SETTINGS AND DESIGN: The survey was carried out among the Bauri tribal community of Purbo Tila village in Moulvibazar District. The community is believed to be the only Bauri community in the country and had four tribal healers who continue their traditional medicinal practices. MATERIALS AND METHODS: Interviews of the healers were carried out with the help of a semi-structured questionnaire and the guided field-walk method where the healers took the interviewers on guided field-walks through areas from where they collected their medicinal plants. Here they identified the plants and described their uses. RESULTS: The Bauri healers were observed to use 40 different plant species and one bird species for treatment of ailments such as fever, respiratory tract disorders, pain, gastrointestinal disorders, eye problems like cataract and conjunctivitis, jaundice, abscess, cardiovascular disorders, urinary problems, paralysis, dog bite, snake bite, helminthiasis, lesions on the tongue or lips and piles. Leaves were the major plant part used and constituted 38.3% of total uses followed by fruits at 14.9%. CONCLUSIONS: A review of the relevant scientific literature showed that a number of medicinal plants used by the Bauri healers possess pharmacological activities, which were in line with the traditional uses, thus validating their use by the Bauri tribe.

Ethnomedicinal plants used by the Nag clan of the Rai Ghatual tribe of Moulvibazar district, Bangladesh.

CONTEXT: Medicinal practices of the tribes of Bangladesh remain largely un-documented. AIMS: The aim of the present study was to conduct an ethnomedicinal survey and documentation among the Nag clan of the Rai Ghatual tribe of Bangladesh. SETTINGS AND DESIGN: The survey was carried out among the Nag clan of the Rai Ghatual tribal community of Moulvibazar district. The clan, according to them, is the only Nag clan of the Rai Ghatual tribe in Bangladesh. The clan has three tribal healers, still continuing their traditional medicinal practices. MATERIALS AND METHODS: Interviews of the healers were carried out with the help of a semi-structured questionnaire and the guided field-walk method. RESULTS: The Nag clan healers were observed to use 28 different plant species distributed into 22 families for treatment of ailments such as fever, loss of appetite, male infertility, dysentery, lower abdominal pain during menstruation, jaundice, stomachache, burning sensations during urination, bodily pain and weak health. CONCLUSIONS: This is the first reported study of the traditional medicinal practices of Nag clan healers. Several of the plants can be validated in their uses on the basis of existing scientific literature. The medicinal plants used by the Nag healers warrant further scientific studies, for the plants are readily available and can form alternative medicinal sources instead of costlier biomedical drugs.

Medicinal plants used by the Mandais--a little known tribe of Bangladesh.

The Mandais are a little known tribe of Bangladesh inhabiting the north central regions, particularly Tangail district of Bangladesh. Their population has been estimated to be less than 10,000 people. Although the tribe has for the most part assimilated with the mainstream Bengali-speaking population, they to some extent still retain their original tribal customs, including their traditional medicinal practices. Since this practice is also on the verge of disappearance, the objective of the present study was to conduct an ethnomedicinal survey among Mandai tribal practitioners to document their use of medicinal plants for treatment of various ailments. Four traditional practitioners were found in the exclusive Mandai-inhabited village of Chokchokia in Tangail district. Information was collected from the practitioners with the help of a semi-structured questionnaire and guided field-walk method. It was observed that the four traditional practitioners used a total of 31 plants distributed into 23 families for treatment. The various ailments treated included diabetes, low semen density, jaundice, gastrointestinal tract disorders (stomach ache, indigestion, dysentery, and diarrhea), leucorrhea, pain (rheumatic pain, joint pain), skin disorders, respiratory tract disorders (coughs, mucus, and allergy), debility, fever, and helminthiasis. From the number of plants used (seven), it appeared that gastrointestinal tract disorders formed the most common ailment among the Mandai community, possibly brought about by the low income status of the people coupled with unhygienic conditions of living.