Determination of changes in the metabolic profile of avocado fruits (Persea americana) by two CE-MS approaches (targeted and non-targeted)

Proximate composition, lipid and elemental profiling of eight varieties of avocado (Persea americana)

Eight Moroccan avocado varieties were analyzed for their nutritional composition and physicochemical properties. The nutritional contents of the sample were determined through the evaluation of the moisture, oil, ash, protein, and carbohydrate contents, and energy value calculation. Additionally, macroelements (Ca, Mg, and Na) and microelements (Fe, Zn, Cu, and Mn) were determined in the mineral profile. Oils were examined also for their fatty acid, phytosterol, and tocopherol profiles. As a result of the study, the avocado presents significant differences between the eight studied varieties (p < 0.05), with regard to moisture content (57.88 g/100 g to 84.71 g/100 g), oil content (8.41 g/100 g to 57.88 g/100 g), ash (0.57 g/100 g to 1.37 g/100 g), protein content (5.7 g/100 g to 8.61 g/100 g), carbohydrate content (5.63 g/100 g to 14.61 g/100 g), and energy value (99.9 kcal/100 g to 316.8 kcal/100 g). Sodium (5783.01 mg/kg to 12,056.19 mg/kg) was the predominant macro-element in all varieties, followed by calcium (295.95 mg/kg to 531.67 mg/kg), and magnesium (246.29 mg/kg to 339.84 mg/kg). Copper (85.92 mg/kg to 112. 31 mg/kg) was the main microelement in all varieties, followed by iron (8.5 mg/kg to 20.32 mg/kg), and manganese (7.3 mg/kg to 18.45 mg/kg), while zinc (1.72 mg/kg to 5.66 mg/kg) was detected in small amounts. In addition, significant difference was observed in lipid profiles, according to the eight studied varieties (p < 0.05). Avocado oils were mainly composed of monounsaturated fatty acids (76.89 g/100 g to 84.7 g/100 g), with oleic acid (50.38 g/100 g to 71.49 g/100 g) standing out as particularly characteristic, while β-sitosterol (l2365.58 mg/kg to 4559.27 mg/kg), and α-tocopherol (30.08 mg/kg to 182.94 mg/kg) were among its major phytosterols and tocopherols. All avocado varieties represented in this study can be consumed as a fruit as an excellent source of energy, minerals, fatty acids, phytosterols, and tocopherols. The regular consumption of this fruit provides the body with several essential nutrients.

Metabolomics-based profiling of 4 avocado varieties using HPLC-MS/MS and GC/MS and evaluation of their antidiabetic activity

Seven avocado “Persea americana” seeds belonging to 4 varieties, collected from different localities across the world, were profiled using HPLC–MS/MS and GC/MS to explore the metabolic makeup variabilities and antidiabetic potential. For the first time, 51 metabolites were tentatively-identified via HPLC–MS/MS, belonging to different classes including flavonoids, biflavonoids, naphthodianthrones, dihydrochalcones, phloroglucinols and phenolic acids while 68 un-saponified and 26 saponified compounds were identified by GC/MS analysis. The primary metabolic variabilities existing among the different varieties were revealed via GC/MS-based metabolomics assisted by unsupervised pattern recognition methods. Fatty acid accumulations were proved as competent, and varietal-discriminatory metabolites. The antidiabetic potential of the different samples was explored using in-vitro amylase and glucosidase inhibition assays, which pointed out to Gwen (KG) as the most potent antidiabetic sample. This could be attributed to its enriched content of poly-unsaturated fatty acids and polyphenolics. Molecular docking was then performed to predict the most promising phytoligands in KG variety to be posed as antidiabetic drug leads. The highest in-silico α-amylase inhibition was observed with chrysoeriol-4′-O-pentoside-7-O-rutinoside, apigenin-7-glucuronide and neoeriocitrin which might serve as potential drug leads for the discovery of new antidiabetic remedies.

The Effect of Hydrothermal Treatment on Metabolite Composition of Hass Avocados Stored in a Controlled Atmosphere

Avocado cv. Hass consumption has expanded worldwide given its nutritional, sensory, and functional attributes. In this work, avocado fruit from two harvests was subjected to hydrothermal treatment (38 °C for 1 h) or left untreated (control) and then stored for 30 and 50 days in a controlled atmosphere (4 kPa O₂ and 6 kPa CO₂ at 7 °C) (HTCA and CA, respectively) with subsequent ripening at ~20 °C. The fruit was evaluated for primary and secondary metabolites at harvest, after storage, and after reaching edible ripeness. A decrease from harvest to edible ripeness in mannoheptulose and perseitol was observed while β-sitosterol, hydrophilic and lipophilic antioxidant activity (H-AOX, L-AOX), abscisic acid, and total phenolics (composed of p-coumaric and caffeic acids such as aglycones or their derivatives) increased. HTCA fruit at edible ripeness displayed higher contents of mannoheptulose, perseitol, β-sitosterol, L-AOX, caffeic acid, and p-coumaric acid derivatives, while CA fruit presented higher contents of α-tocopherol, H-AOX, and syringic acid glycoside for both harvests and storage times. The results indicate that a hydrothermal treatment prior to CA enables fruit of high nutritional value characterized by enhanced content of phenolic compounds at edible ripeness to reach distant markets.

Primary Metabolism in Avocado Fruit

Avocado (Persea americana Mill) is rich in a variety of essential nutrients and phytochemicals; thus, consumption has drastically increased in the last 10 years. Avocado unlike other fruit is characterized by oil accumulation during growth and development and presents a unique carbohydrate pattern. There are few previous and current studies related to primary metabolism. The fruit is also quite unique since it contains large amounts of C7 sugars (mannoheptulose and perseitol) acting as transportable and storage sugars and as potential regulators of fruit ripening. These C7 sugars play a central role during fruit growth and development, but still confirmation is needed regarding the biosynthetic routes and the physiological function during growth and development of avocado fruit. Relatively recent transcriptome studies on avocado mesocarp during development and ripening have revealed that most of the oil is synthesized during early stages of development and that oil synthesis is halted when the fruit is harvested (pre-climacteric stage). Most of the oil is accumulated in the form of triacylglycerol (TAG) representing 60-70% in dry basis of the mesocarp tissue. During early stages of fruit development, high expression of transcripts related to fatty acid and TAG biosynthesis has been reported and downregulation of same genes in more advanced stages but without cessation of the process until harvest. The increased expression of fatty acid key genes and regulators such as PaWRI1, PaACP4-2, and PapPK-β-1 has also been reported to be consistent with the total fatty acid increase and fatty acid composition during avocado fruit development. During postharvest, there is minimal change in the fatty acid composition of the fruit. Almost inexistent information regarding the role of organic acid and amino acid metabolism during growth, development, and ripening of avocado is available. Cell wall metabolism understanding in avocado, even though crucial in terms of fruit quality, still presents severe gaps regarding the interactions between cell wall remodeling, fruit development, and postharvest modifications.

Polyphenolic Profile and Antioxidant Activity of Leaf Purified Hydroalcoholic Extracts from Seven Mexican Persea americana Cultivars

Persea americana (avocado) is a fruit consumed worldwide; however, since avocado leaves are apparently a natural ingredient that can be used as a traditional medicine, they can be a potential source of bioactive compounds. This study aimed to analyze the antioxidant activity of seven Mexican avocado leaf extracts by DPPH^•, ABTS^•+, and lipid peroxidation (LPO), and to identify the compound profile by liquid chromatography coupled to mass spectrometry/electron spray ionization. The highest free radical-scavenging activity was observed for Platano Delgado and Criollo 6 avocado cultivars havin IC₅₀ values of 271.86 ± 13.69 and 269.56 ± 6.53 for DPPH^• and ABTS^•+ radicals, respectively, while the best result for lipid oxidation inhibition was registered in Criollo 6 cultivar extract. In this study forty-one compounds were detected in avocado leaves of the the seven cultivars analyzed, and of these compounds, eighteen phenolics were identified for first time in such plant material. The present study demonstrated that Mexican cultivars of Persea americana possess diverse polyphenolic compounds with strong antioxidant activity, which might be useful in the food and pharmaceutical industries.