Valorization potential of Egyptian mango kernel waste product as analyzed via GC/MS metabolites profiling from different cultivars and geographical origins

www.nature.com/scientificreports OPEN Valorization potential of Egyptian mango kernel waste product as analyzed via GC/MS metabolites profiling from different cultivars and geographical origins Rehan M. El‑Shabasy 1, Tarek F. Eissa 2, Yossef Emam 3, Ahmed Zayed 4, Nesrin Fayek 3 & Mohamed A. Farag 3* Increasing attention has been given to mango (Mangifera indica) fruits owing to their characteristic taste, and rich nutritional value. Mango kernels are typically discarded as a major waste product in mango industry, though of potential economic value. The present study aims to outline the first comparison of different mango kernel cvs. originated from different localities alongside Egypt, e.g., Sharqia, Suez, Ismailia, and Giza. Gas chromatography–mass spectroscopy (GC–MS) post silylation analysis revealed that sugars were the major class being detected at 3.5–290.9 µg/mg, with some kernels originating from Sharqia province being the richest amongst other cvs. In consistency with sugar results, sugar alcohols predominated in Sharqia cvs. at 1.3–38.1 µg/mg represented by ribitol, iditol, pinitol, and myo-inositol. No major variation was observed in the fatty acids profile either based on cv. type or localities, with butyl caprylate as a major component in most cvs. identified for the first time in mango. Regarding phenolics, Sedeeq cv. represented the highest level at 18.3 µg/mg and showing distinct variation among cvs. posing phenolics as better classification markers than sugars. Multivariate data analyses (MVA) confirmed that the premium cvs “Aweis and Fons” were less enriched in sugars, i.e., fructose, talose, and glucose compared to the other cvs. Moreover, MVA of Zabdeya cv. collected from three localities revealed clear segregation to be chemically distinct. Sharqia originated mango kernels were rich in sugars (e.g., glucose and fructose), whilst sarcosine esters predominated in other origins. Mango (Mangifera indica) is a widely popular tropical fruit belonging to Anacardiaceae family. It is known as the king of fruits owing for its delicious taste, fragrance and potential nutritional value1. Mango fruit varies in shape, size, flesh and peel color, taste and aroma, that are all basically dependent on cultivar t ype2. Mango increasing economic potential in the global m arket3, is manifested by its high production yield of mango to rank as the predominant tropical fruit in the twenty-first century4. Mango ranks the 5th amongst most cultivated fruit crops worldwide owing for its rich nutrient composition and p hytochemicals5. It is grown in over 90 countries to amount for ca. 50% of tropical fruits produced worldwide6. The world production of mango cultivars reached 55.9 million tons in 2 0197. The majority of mango trees is cultivated in Asia in particular I ndia8 as a major exporter to yield 17–23 million t ons9. Mango has widely emerged in other countries including China, Indonesia, Thailand and Egypt to all account for 80% of the total world p roduction1. As a major fruit crop, it is represented by 1000 cvs., though only few of them are cultivated (30)1. Among worldwide sources of mango, Egyptian mango has gained increasing attention due to its remarkable flavor and taste among c onsumers10. In our previous publication, various cvs. have been investigated, specifically their pulp, based on their volatiles and bioactive compounds using solid-phase microextraction coupled with gas 1 Chemistry Department, Faculty of Science, Menofia University, Shebin El‑Kom 32512, Egypt. 2Faculty of Biotechnology, October University for Modern Sciences and Arts (MSA), Giza 12451, Egypt. 3Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr El Aini St., P.B. 11562, Cairo, Egypt. 4Pharmacognosy Department, College of Pharmacy, Tanta University, Elguish Street (Medical Campus), Tanta 31527, Egypt. *email: Scientific Reports | (2024) 14:2886 | https://doi.org/10.1038/s41598-024-53379-4 1 Vol.:(0123456789) www.nature.com/scientificreports/ chromatography/mass spectroscopy (SPME-GC/MS)10 and bioactive secondary metabolites using ultra-performance liquid chromatography (UPLC) coupled to MS (UPLC/MS) and in relation to its antioxidant activity11. According to the development of functional foods, mango peel powder has been included in bakery products, jellies and pastas attributed to its potential antioxidant activity and glycemic index, while mango peels extracts were incorporated in co-pigments and lipid peroxidation inhibitors12. These effects have yet to be examined for mango kernels though unlikely as no carotenoids are reported in kernels compared to their richness in fruit pulp and peel13. In recent years, several spectroscopic techniques including mostly hyphenated techniques such as gas/liquidchromatography coupled to mass-spectroscopy (GC/LC–MS) analysed using multivariate data analyses (MVA) have greatly aided in the holistic characterization of metabolome, and further in samples classification in response to different status or p henotypes11,14. Multivariate data analyses (MVA) are typically employed in unsupervised mode, such as principal component analysis (PCA), or supervised one exemplified by orthogonal partial leastsquares discriminant analysis (OPLS-DA) for visualization of the rich spectral datasets. Both are routinely incorporated for the classification of investigated specimens, and products fingerprinting and authentication for quality control purposes15. Such an approach has increasingly been used for quality control of functional foods in the context of determination of freshness, geographical and genotype, processing, and or adulteration detection11. Following the potential economic value of mango fruits in the world market, we have previously reported on the use of MVA for classification of Egyptian mango cvs. Egypt’s total area under mango cultivation reached 130,000 ha with a total production of 766,128 tons regarded as the most important fruit crop cultivated in all Egyptian province16. Fourteen cultivars of mango fruits from different localities were subjected to aroma profiling using headspace solid phase microextraction SPME coupled with gas chromatography mass spectroscopy (GC–MS)10, and revealing for distinct aroma profile especially for premium mango cvs. such as Awees being enriched in t erpenes10. More recently, liquid chromatography mass spectrometry and in comparison, to UV fingerprinting were employed for classification of mango fruit cvs. targeting their specialized metabolites in context to different cvs. and or geographical origin in Egypt11. A potential classification was observed from both analytical platforms viz. Ultra-performance liquid chromatography-mass spectrometry (UPLC/MS) and UV spectroscopy, revealing for higher phenolic content in premium Aweis cv concurrent with potential antioxidant effect11. UPLC/ MS led to the identification of 47 peaks belonging to tannins as gallic acid esters, flavonoids, xantho (...truncated)