The peel and pulp of mango fruit: A proteomic samba

Comparing and integrating TMT-SPS-MS3 and label-free quantitative approaches for proteomics scrutiny in recalcitrant Mango (Mangifera indica L.) peel tissue during postharvest period

Despite substantial advances in the use of proteomic technologies, their widespread application in fruit tissues of non-model and recalcitrant species remains limited. This hampers the understanding of critical molecular events during the postharvest period of fleshy tropical fruits. Therefore, we evaluated label-free quantitation (LFQ) and TMT-SPS-MS3 (TMT) approaches to analyse changes in the protein profile of mango peels during postharvest period. We compared two extraction methods (phenol and chloroform/methanol) and two peptide fractionation schemes (SCX and HPRP). We accurately identified 3065 proteins, of which, 1492 were differentially accumulated over at 6 days after harvesting (DAH). Both LFQ and TMT approaches share 210 differential proteins including cell wall proteins associated with fruit softening, as well as aroma and flavour-related proteins, which were increased during postharvest period. The phenolic protein extraction and the high-pH reverse-phase peptide fractionation was the most effective pipeline for relative quantification. Nevertheless, the information provided by the other tested strategies was significantly complementary. Besides, LFQ spectra allowed us to track down intact N-glycopeptides corroborating N-glycosylations on the surface of a desiccation-related protein. This work represents the largest proteomic comparison of mango peels during postharvest period made so far, shedding light on the molecular foundation of edible fruit during ripening.

Advances in Physiological, Transcriptomic, Proteomic, Metabolomic, and Molecular Genetic Approaches for Enhancing Mango Fruit Quality

Mango (Mangifera indica L.) is a nutritionally important fruit of high nutritive value, delicious in taste with an attractive aroma. Due to their antioxidant and therapeutic potential, mango fruits are receiving special attention in biochemical and pharmacognosy-based studies. Fruit quality determines consumer's acceptance, and hence, understanding the physiological, biochemical, and molecular basis of fruit development, maturity, ripening, and storage is essential. Transcriptomic, metabolomic, proteomic, and molecular genetic approaches have led to the identification of key genes, metabolites, protein candidates, and quantitative trait loci that are associated with enhanced mango fruit quality. The major pathways that determine the fruit quality include amino acid metabolism, plant hormone signaling, carbohydrate metabolism and transport, cell wall biosynthesis and degradation, flavonoid and anthocyanin biosynthesis, and carotenoid metabolism. Expression of the polygalacturonase, cutin synthase, pectin methyl esterase, pectate lyase, β-galactosidase, and ethylene biosynthesis enzymes are related to mango fruit ripening, flavor, firmness, softening, and other quality processes, while genes involved in the MAPK signaling pathway, heat shock proteins, hormone signaling, and phenylpropanoid biosynthesis are associated with diseases. Metabolomics identified volatiles, organic acids, amino acids, and various other compounds that determine the characteristic flavor and aroma of the mango fruit. Molecular markers differentiate the mango cultivars based on their geographical origins. Genetic linkage maps and quantitative trait loci studies identified regions in the genome that are associated with economically important traits. The review summarizes the applications of omics techniques and their potential applications toward understanding mango fruit physiology and their usefulness in future mango breeding.

Fruit quality parameters and volatile compounds from 'Palmer' mangoes with internal breakdown

The internal breakdown (IB) is a premature and uneven mango pulp ripening physiological disorder that is noticed only when the fruit is sliced for consumption. Thus, there is a demand for analytical methods to detect IB in mangoes to avoid consumer dissatisfaction and reduce postharvest waste. In this work, physicochemical and volatile compounds were determined to evaluate the ability to predict pulp IB. Principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the data show that color, firmness, and volatiles compounds are important to give some information about the physiological changes caused by IB. The volatile compounds methacrylic acid, ethyl ester, isopentyl ethanoate, limonene oxide, (E)-2-pentenal, tetradecane, and γ-elemene were identified as chemical markers of IB. Therefore, mango physical and chemical characteristics combined with PCA and PLS-DA were successfully employed for the identification of IB in mangoes, showing significant differences between healthy and IB fruits.

Isolation and functionalities of bioactive peptides from fruits and vegetables: A reviews

Bioactive peptides have recently gained more research attention as potential therapies for the management of bodily disorders and metabolic syndromes of delicate health importance. On another note, there is a rising trend on a global scale for the consumption and adoption of fruit and vegetables for the fulfilment of dietary and health needs. Furthermore, fruits and vegetables are being more studied as base materials for the isolation of biologically functional components and accordingly, they have been investigated for their concomitant bioactive peptides. This review focuses on isolation and bio-functional properties of bioactive peptides from fruits and vegetables. This manuscript is potential in serving as a material collection for fundamental consultancy on peptides derived from fruits and vegetables, and further canvasses the necessitation for the use of these food materials as primal matter for such.

Detection of Plant Low-Abundance Proteins by Means of Combinatorial Peptide Ligand Library Methods

The detection and identification of low-abundance proteins from plant tissues is still a major challenge. Among the reasons are the low protein content, the presence of few very high-abundance proteins, and the presence of massive amounts of other biochemical compounds. In the last decade numerous technologies have been devised to resolve the situation, in particular with methods based on solid-phase combinatorial peptide ligand libraries. This methodology, allowing for an enhancement of low-abundance proteins, has been extensively applied with the advantage of deciphering the proteome composition of various plant organs. This general methodology is here described extensively along with a number of possible variations. Specific guidelines are suggested to cover peculiar situations or to comply with other associated analytical methods.

Low-abundance plant protein enrichment with peptide libraries to enlarge proteome coverage and related applications

In plant tissues proteins are present in low amounts but in a very large number. To this peculiar situation many complex foreign components render protein extraction and purification very difficult. In the last several years interesting technologies have been described to improve the technical situation to the point that some methodologies allow reaching very low-abundance proteins and minor allergens. Among enrichment methods the one documented in this report is based on combinatorial peptide ligand libraries (CPLLs) that emerged in the last decade by contributing to largely improve the knowledge in plant proteomics. It is the aim of this review to describe how this technology allows detecting low-abundance proteins from various plant tissues and to report the dynamics of the proteome components in response to environmental changes and biotic attacks. Typical documented examples with the description of their scientific interest are reported. The described technical approach and selected applications are considered as one of the most advanced approaches for plant proteomics investigations with possibilities not only to enlarge the knowledge of plant proteomes but also to discover novel allergens as well as plant biomarkers subsequent to stressful situations.

Properties of Pectin Extracted from Vietnamese Mango Peels

This study was carried out to investigate the properties of pectin extracted from Vietnamese mango peels that have been discarded as waste. Three different mango cultivars named Hoa Loc, Ghep and Cat Chu at three different maturities were studied. Pectin extracted from immature, ripe and overripe stages ranged from 18.4 to 31.7 g/100 g dry weight (DW); the highest yields were obtained from the ripe fruits. Ghep peels contained the highest pectin amounts which ranged from 24.2 to 31.7 g/100 g DW, followed by Cat Chu (19.2 to 26.5 g/100 g DW) and Hoa Loc peels (18.4 to 24.1 g/100 g DW). Except for degree of esterification and emulsion capacity, other properties of the extracted pectin including water holding capacity, solubility and emulsion stability were significantly affected by the fruit maturation. Varieties, solubility, degree of esterification, emulsion activity and emulsion stability of the pectin isolated from the three cultivars ranged from 77.4% to 86.0%; 50.3% to 55.8%; 11.8% to 34.3% and 28.5% to 94.5%, respectively. Fourier-transform infrared results showed that almost all collected pectin samples could be classified as the high methoxyl pectin. Rheology data indicated viscosity of the isolated pectin was strongly dependent on temperatures.

IgE Cross-Reactivity of Cashew Nut Allergens

BACKGROUND

Allergic sensitisation towards cashew nut often happens without a clear history of eating cashew nut. IgE cross-reactivity between cashew and pistachio nut is well described; however, the ability of cashew nut-specific IgE to cross-react to common tree nut species and other Anacardiaceae, like mango, pink peppercorn, or sumac is largely unknown.

OBJECTIVES

Cashew nut allergic individuals may cross-react to foods that are phylogenetically related to cashew. We aimed to determine IgE cross-sensitisation and cross-reactivity profiles in cashew nut-sensitised subjects, towards botanically related proteins of other Anacardiaceae family members and related tree nut species.

METHOD

Sera from children with a suspected cashew nut allergy (n = 56) were assessed for IgE sensitisation to common tree nuts, mango, pink peppercorn, and sumac using dot blot technique. Allergen cross-reactivity patterns between Anacardiaceae species were subsequently examined by SDS-PAGE and immunoblot inhibition, and IgE-reactive allergens were identified by LC-MS/MS.

RESULTS

From the 56 subjects analysed, 36 were positive on dot blot for cashew nut (63%). Of these, 50% were mono-sensitised to cashew nuts, 19% were co-sensitised to Anacardiaceae species, and 31% were co-sensitised to tree nuts. Subjects co-sensitised to Anacardiaceae species displayed a different allergen recognition pattern than subjects sensitised to common tree nuts. In pink peppercorn, putative albumin- and legumin-type seed storage proteins were found to cross-react with serum of cashew nut-sensitised subjects in vitro. In addition, a putative luminal binding protein was identified, which, among others, may be involved in cross-reactivity between several Anacardiaceae species.

CONCLUSIONS

Results demonstrate the in vitro presence of IgE cross-sensitisation in children towards multiple Anacardiaceae species. In this study, putative novel allergens were identified in cashew, pistachio, and pink peppercorn, which may pose factors that underlie the observed cross-sensitivity to these species. The clinical relevance of this widespread cross-sensitisation is unknown.

Novel low-abundance allergens from mango via combinatorial peptide libraries treatment: A proteomics study

Mango allergy is a rare condition, which may cause severe hypersensitivity reactions, such as anaphylaxis, angioedema, asthma and contact dermatitis. By exploiting the combinatorial peptide ligand library (CPLL) technology, mango proteomes have been extracted and the presence of traces of allergens assessed via Western blot analysis two-dimensional maps. Upon reactive spot elution and mass spectrometry analyses, four major mango allergens could be identified for the first time and shown to be in common with three of the five known banana species. These allergens include: Mus a 1, Mus a 2 and Mus a 5. Additional mango allergens detected do not seem to be in common with the banana species. In particular, a pectinesterase and a superoxide dismutase, both widely described as allergens, could be identified in mango extracts. Conversely, plain mango extracts not treated with CPLLs did not exhibit any reactive spots in Western blot analysis.

Transcriptional transitions in Alphonso mango (Mangifera indica L.) during fruit development and ripening explain its distinct aroma and shelf life characteristics

Alphonso is known as the “King of mangos” due to its unique flavor, attractive color, low fiber pulp and long shelf life. We analyzed the transcriptome of Alphonso mango through Illumina sequencing from seven stages of fruit development and ripening as well as flower. Total transcriptome data from these stages ranged between 65 and 143 Mb. Importantly, 20,755 unique transcripts were annotated and 4,611 were assigned enzyme commission numbers, which encoded 142 biological pathways. These included ethylene and flavor related secondary metabolite biosynthesis pathways, as well as those involved in metabolism of starch, sucrose, amino acids and fatty acids. Differential regulation (p-value ≤ 0.05) of thousands of transcripts was evident in various stages of fruit development and ripening. Novel transcripts for biosynthesis of mono-terpenes, sesqui-terpenes, di-terpenes, lactones and furanones involved in flavor formation were identified. Large number of transcripts encoding cell wall modifying enzymes was found to be steady in their expression, while few were differentially regulated through these stages. Novel 79 transcripts of inhibitors of cell wall modifying enzymes were simultaneously detected throughout Alphonso fruit development and ripening, suggesting controlled activity of these enzymes involved in fruit softening.

Current trends of tropical fruit waste utilization

Recent rapid growth of the world's population has increased food demands. This phenomenon poses a great challenge for food manufacturers in maximizing the existing food or plant resources. Nowadays, the recovery of health benefit bioactive compounds from fruit wastes is a research trend not only to help minimize the waste burden, but also to meet the intensive demand from the public for phenolic compounds which are believed to have protective effects against chronic diseases. This review is focused on polyphenolic compounds recovery from tropical fruit wastes and its current trend of utilization. The tropical fruit wastes include in discussion are durian (Durio zibethinus), mangosteen (Garcinia mangostana L.), rambutan (Nephelium lappaceum), mango (Mangifera indica L.), jackfruit (Artocarpus heterophyllus), papaya (Carica papaya), passion fruit (Passiflora edulis), dragon fruit (Hylocereus spp), and pineapple (Ananas comosus). Highlights of bioactive compounds in different parts of a tropical fruit are targeted primarily for food industries as pragmatic references to create novel innovative health enhancement food products. This information is intended to inspire further research ideas in areas that are still under-explored and for food processing manufacturers who would like to minimize wastes as the norm of present day industry (design) objective.

Dynamic range compression with ProteoMiner™: principles and examples

One of the main challenges in proteomics investigation, protein biomarker research, and protein purity and contamination analysis is how to efficiently enrich and detect low-abundance proteins in biological samples. One approach that makes the detection of rare species possible is the treatment of biological samples with solid-phase combinatorial peptide ligand libraries, ProteoMiner. This method utilizes hexapeptide bead library with huge diversity to bind and enrich low-abundance proteins but remove most of the high-abundance proteins, therefore compresses the protein abundance range in the samples. This work describes optimized protocols and highlights on the successful application of ProteoMiner to protein identification and analysis.

Antidiabetic potential of some less commonly used plants in traditional medicinal systems of India and Nigeria

The incidence of diabetes mellitus continue to rise annually all over the world with India and Nigeria having recorded cases of 65.1 and 3.9 million respectively in 2013 and expected to increase by a large amount in 2035. Hyperglycemia is a pre-condition for the development of diabetic complications and is accompanied by an increase in the production of free radicals. The present available treatment option for diabetes like sulfonylurea, metformin and alpha-glucosidase are restricted by their limited actions, secondary failure rates, and side-effects; and unaffordable to the majority of the population. Hence, the need to screen for more medicinal plants with antidiabetic ability due to the fact that plants are; biodegradable, safe and cheap with fewer side-effects. In this review article, we have presented the current status of diabetes in India and Nigeria and the role of some less commonly used medicinal plants from both countries that have antidiabetic potential.

The "Dark Side" of Food Stuff Proteomics: The CPLL-Marshals Investigate

The present review deals with analysis of the proteome of animal and plant-derived food stuff, as well as of non-alcoholic and alcoholic beverages. The survey is limited to those systems investigated with the help of combinatorial peptide ligand libraries, a most powerful technique allowing access to low- to very-low-abundance proteins, i.e., to those proteins that might characterize univocally a given biological system and, in the case of commercial food preparations, attest their genuineness or adulteration. Among animal foods the analysis of cow's and donkey's milk is reported, together with the proteomic composition of egg white and yolk, as well as of honey, considered as a hybrid between floral and animal origin. In terms of plant and fruits, a survey is offered of spinach, artichoke, banana, avocado, mango and lemon proteomics, considered as recalcitrant tissues in that small amounts of proteins are dispersed into a large body of plant polymers and metabolites. As examples of non-alcoholic beverages, ginger ale, coconut milk, a cola drink, almond milk and orgeat syrup are analyzed. Finally, the trace proteome of white and red wines, beer and aperitifs is reported, with the aim of tracing the industrial manipulations and herbal usage prior to their commercialization.