Purified avocado seed acetogenins: Antimicrobial spectrum and complete inhibition of Listeria monocytogenes in a refrigerated food matrix

Bioaccessibility of bioactive compounds present in Persea americana Mill. seed ingredient during oral-gastric digestion with antibacterial capacity against Helicobacter pylori

ETHNOPHARMACOLOGICAL RELEVANCE

In ancient Mexican cultures, the Persea americana Mill seed has been used against gastrointestinal diseases, due to high concentrations of bioactive compounds. According to Traditional Mexican Medicine, P. americana seed aqueous infusion is used against roundworms, intestinal worms, parasites, and gastrointestinal problems, in a dose taken over three or four days. In addition, Mexican Society of Natural History indicates the traditional use of P. americana seed powder as an antiparasitic, and antibacterial. On the other hand, Helicobacter pylori infection is a factor associated with the development of gastric disease, peptic ulcers as well as some types of gastric lymphomas and gastric cancer in humans; in this way is necessary scientific evidence about P. americana seed effect in gastrointestinal disease.

AIM OF THE STUDY

The work aimed to evaluate bioactive compounds bioaccessibility and antimicrobial potential against Helicobacter pylori during oral-gastric digestion in vitro of food ingredient from Persea americana Mill. seed and elucidate the possible action mechanism using in silico tools.

MATERIALS AND METHODS

Initially, P. americana seed oil and aqueous extract of P. americana seed were obtained using ultrasound and maceration respectively, and the food ingredient from P. americana seed was obtained. The samples underwent oral-gastric digestions by the INFOGEST method, to continue identifying and quantifying the bioactive compounds by HPLC-DAD and GC-MS. The anti-Helicobacter pylori activity determination were used fourteen Helicobacter pylori clinical strains and reference strains by Susceptibility testing by Minimal Inhibition Concentration, Kinetics of Growth Inhibition of H. pylori, Urease Inhibitory Kinetic. Finally, to elucidate a possible action mechanism used in silico tools (Software AutoDock 4.2.6 and BioVia Discovery v.19.1.0.1.18287).

RESULTS

The lipophilic fraction of P. americana seed detected oleic acid, linoleic acid, and avocadenofuran compounds, and the phenolic fraction showed the presence of catechin, rutin, ellagic, and chlorogenic acid, among others. Phenolic compounds conformational changes during oral-gastric digestion due to mechanical and acid hydrolysis, while lipophilic compounds showed a 20% increase in the gastric phase. Persea americana Mill. seed ingredient (3.08 μg/mL) showed total in vitro inhibition of clinical and reference strains of H. pylori, likewise, the lipophilic fraction had a lower inhibition concentration (2.59 μg/mL) regardless of the strains. Among the mechanisms found in silico, inhibition of target proteins such as CagA, BabA, and MUC5 were observed, as virulence factors involving adherence and bacterial pathogenicity.

CONCLUSIONS

This research provides evidence that food ingredient from P. americana seed has antimicrobial in vitro potential against H. pylori clinical strains, through phenolic and mainly lipophilic compounds, opening new scientific evidence that supports the P. americana seed's traditional use.

Comprehensive Review on Fruit Seeds: Nutritional, Phytochemical, Nanotechnology, Toxicity, Food Biochemistry, and Biotechnology Perspective

Fruit seeds are leftovers from a variety of culinary sectors. They are generally unutilized and contribute greatly to global disposals. These seeds not only possess various nutritional attributes but also have many heath-beneficial properties. One way to make use of these seeds is to extract their bioactive components and create fortified food items. Nowadays, researchers are highly interested in creating innovative functional meals and food components from these unconventional resources. The main objective of this manuscript was to determine the usefulness of seed powder from 70 highly consumed fruits, including Apple, Apricot, Avocado, Banana, Blackberry, Blackcurrant, Blueberry, Cherry, Common plum, Cranberry, Gooseberry, Jackfruit, Jamun, Kiwi, Lemon, Mahua, Mango, Melon, Olive, Orange, and many more have been presented. The nutritional attributes, phytochemical composition, health advantages, nanotechnology applications, and toxicity of these fruit seeds have been fully depicted. This study also goes into in-depth detailing on creating useful food items out of these seeds, such as bakery goods, milk products, cereal-based goods, and meat products. It also identifies enzymes purified from these seeds along with their biochemical applications and any research openings in this area.

Aboyewa J, Moabelo KL, Sibuyi NRS, Meyer S, Onani MO, Meyer M, Madiehe AM. Anticancer, Antioxidant, and Catalytic Activities of Green Synthesized Gold Nanoparticles Using Avocado Seed Aqueous Extract

Disposal of agricultural waste has a negative impact on the environment and human health and may contribute to the greenhouse effect. The field of nanotechnology could provide alternative solutions to upcycle agricultural wastes in a safer manner into high-end value products. Organic waste from plants contain biomaterials that could serve as reducing and capping agents in the synthesis of nanomaterials with enhanced activities for use in biomedical and environmental applications. Persea americana (avocado) is a fruit with a high nutritional value; however, despite its rich phytochemical profile, its seed is often discarded as waste. Therefore, this study aimed to upcycle avocado seeds through the synthesis of gold nanoparticles (AuNPs) and evaluate their anticancer, antioxidant, and catalytic activities. The biosynthesis of avocado seed extract (AvoSE)-mediated AuNPs (AvoSE-AuNPs) was achieved following the optimization of various reaction parameters, including pH, temperature, extract, and gold salt concentrations. The AvoSE-AuNPs were poly-dispersed and anisotropic, with average core and hydrodynamic sizes of 14 ± 3.7 and 101.39 ± 1.4 nm, respectively. The AvoSE-AuNPs showed excellent antioxidant potential in terms of ferric reducing antioxidant power (343.88 ± 0.001 μmolAAE/L), 2,2-diphenyl-1-picrylhydrazyl (128.80 ± 0.0159 μmolTE/L), and oxygen radical absorbance capacity (1822.02 ± 12.6338 μmolTE/L); significantly reduced the viability of Caco-2 and PC-3 cells in a dose-dependent manner; and efficiently reduced 4-nitrophenol (4-NP) to 4-aminophenol. This study demonstrated how avocado seeds, an agricultural waste, can be used as sources of new bioactive materials for the synthesis of AuNPs, which have excellent antioxidant, anticancer, and catalytic activities, showing AvoSE-AuNPs' versatility in various applications. In addition, the AvoSE-AuNPs exhibited good stability and recyclability during the catalytic activity, which is significant because some of the primary issues with the use of metallic NPs as catalysts are around the cost-effectiveness, recovery, and reusability of the catalyst.

Avocado seed discoveries: Chemical composition, biological properties, and industrial food applications

The processing industry discards avocado seeds, which increases production and ultimately pollutes the environment. It would be advantageous to handle these waste by-products both economically and environmentally. Avocado seeds are rich in polysaccharides, proteins, lipids, vitamins, minerals, and other bioactive substances. The nutritional and phytochemical composition of avocado seeds has been well studied and discussed. Avocado-seed extracts also have many health-related bioactive properties, such as anti-hyperglycaemic, anticancer, anti-hypercholesterolemia, antioxidant, anti-inflammatory, and anti-neurogenerative effects are clearly demonstrated how these properties can be used to formulate or fortify food. The health-promoting properties of avocado seeds have been studied. These properties are attributed to various phytochemicals, such as acetogenin, catechin, epicatechin, procyanidin B1, estragole, etc. Additionally, items made from valorized avocado seeds that people can consume have been explored. The best applications of valorized by-products have been created for the pharmaceutical, functional food, and nutraceutical sectors while considering quality and safety. More clinical testing and product development research are required to prove the effectiveness of avocado seeds.

Food and cosmetic applications of the avocado seed: a review

Avocado seed waste has increased as avocado products have become commercialized since the seed is considered inedible. However, by exploring the potential uses of the seed, the unrecyclable waste produced by the avocado industry can be reduced. This paper aims to review and discuss current literature on the food and cosmetic applications of avocado seeds and their constituents. In descending order, avocado seeds contain starch, water, lipids, protein, phytochemicals, antinutrients, vitamins, and minerals. As for food applications, starch can be used as a bioplastic, flour, thickening agent, and emulsifier. Additionally, extracts containing avocado seed phytochemicals show antimicrobial and preservative activities, which can find use in meat products and in producing an orange dye. When considering cosmetic applications, patented avocado seed extract formulations have proven useful in skincare. Also, the avocado seed lipids, in the form of fatty acids, can be processed into soap. By applying the ideas presented in this review, the toll avocado seeds take on the environment would be reduced, improving the sustainability of the avocado market. As a result, avocado seeds can contribute to the emerging bioeconomy market for food and cosmetic applications.

Avocado seeds (Persea americana cv. Criollo sp.): Lipophilic compounds profile and biological activities

This study aimed to evaluate the volatile or lipophilic chemical profiling and the biological activities of avocado (Persea americana cv. Criollo sp.) seed extracts. Chemical profile of volatile compounds (GC/MS), antioxidant properties (phenolic compounds, DPPH radical scavenging activities and reducing power), and antimicrobial activity (Salmonella Typhimurium and Staphylococcus aureus) of avocado (Persea americana cv. Criollo sp.) seed extracts (ethanol and acetone) were characterized. Sixteen volatile chemical compounds were determined, including isoprenoid derivatives (estragole), esters of fatty acids (linoleic and linolenic acids), and their derivatives (9,12-Octadecadien-1-ol and 9,12,15-Octadecatrien-1-ol). Acetone was the best solvent to obtain volatile compounds from avocado seed; this extract also showed a higher reducing power (56.35 mg AAE/100 g). Maximum S. aureus and S. Typhimurium log reductions were 4.0 ± 0.3 and 1.8 ± 0.3 at the highest amount used (2000 mg/L), without significant effect (p < 0.05) of the solvent used. According to the results of the volatile chemical profiling of avocado (Persea americana cv. Criollo sp.) seed extracts, they can have potential application as antioxidant (212.75 and 183.75 mg Trolox/100 g) and antimicrobial additives.

Persea Americana Agro-Industrial Waste Biorefinery for Sustainable High-Value-Added Products

Significant problems have arisen in recent years, such as global warming and hunger. These complications are related to the depletion and exploitation of natural resources, as well as environmental pollution. In this context, bioprocesses and biorefinery can be used to manage agro-industrial wastes for obtaining high-value-added products. A large number of by-products are composed of lignin and cellulose, having the potential to be exploited sustainably for chemical and biological conversion. The biorefinery of agro-industrial wastes has applications in many fields, such as pharmaceuticals, medicine, material engineering, and environmental remediation. A comprehensive approach has been developed toward the agro-industrial management of avocado (Persea americana) biomass waste, which can be transformed into high-value-added products to mitigate global warming, save non-renewable energy, and contribute to health and science. Therefore, this work presents a comprehensive review on avocado fruit waste biorefinery and its possible applications as biofuel, as drugs, as bioplastics, in the environmental field, and in emerging nanotechnological opportunities for economic and scientific growth.

Tissue-specific proteome characterization of avocado seed during postharvest shelf life

Avocado is a nutritious and economically important fruit, generating significant income for exporter countries. Recently, by-products of this fruit such as seeds and peels, have raised interest in different industries. However, the biochemical features of the nutraceutical value of these tissues have not been analyzed using molecular approaches during the postharvest shelf life (PSL). We carried out comparative proteomics using tandem mass tagging (TMT) and synchronous-precursor selection (SPS)-MS³. We analyzed testa, cotyledon, and embryo axes from avocado seeds at detachment from the tree (unripe), and after five (breaker) and ten days (ripe) of PSL. We identified 1968 proteins, from which 933 were specific to the testa, 167 to the embryo axis, and 23 to the cotyledon. The testa had a more dynamic proteome than the other tissues, resembling similar stress responses to those observed in peel tissues, such as down-accumulation of translational machinery, cell wall catabolism and synthesis of secondary metabolites. In contrast, the up-accumulation of the biosynthesis of l-glutamine, L-isoleucine, and l-serine was observed in all tissues. Our study provides the basic biochemical and physiological features of avocado seed during PSL and demonstrates that avocado seed tissues could potentially be used as a costless source of high-value compounds. SIGNIFICANCE: Avocado seed as a fruit by-product is a source of different valuable molecules, including those with nutraceutical properties. During PSL, several biochemical and physiological modifications occur in this dispersal unit, which also includes the alteration of several key metabolites' content. However, the proteome profile associated with different metabolic pathways that regulate the inner content of seed metabolites has not been previously studied. Our tissue-specific proteomics TMT-SPS-MS³-based provides the first evidence of molecular and physiological changes in avocado tissues during PSL delivering fundamental knowledge of this organ. In this vein, the modulation of secondary metabolites, amino acid, and sugar metabolism of avocado tissues during PLS can encourage these by-products exploitation in multiple industries.

Avocado fruit and by-products as potential sources of bioactive compounds

The increased demand for avocado, and therefore production and consumption, generate large quantities of by-products such as seeds, peel, and defatted pulp, which account for approximately 30% of fruit weight, and which are commonly discarded and wasted. The present review focuses on various compounds present in avocado fruit and its by-products, with particular interest to those that can be potentially used in different industrial forms, such as nutraceuticals, to add to or to formulate functional foods, among other uses. Main molecular families of bioactive compounds present in avocado include phenolic compounds (such as hydroxycinnamic acids, hydroxybenzoic acids, flavonoids and proanthocyanins), acetogenins, phytosterols, carotenoids and alkaloids. Types, contents, and possible functions of these bioactive compounds are described from a chemical, biological, and functional approach. The use of avocado and its by-products requires using processing methods that allow highest yield with the least amount of unusable residues, while also preserving the integrity of bioactive compounds of interest. Avocado cultivar, fruit development, ripening stage, and processing methods are some of the main factors that influence the type and amount of extractable molecules. The phytochemical diversity of avocado fruit and its by-products make them potential sources of nutraceutical compounds, from which functional foods can be obtained, as well as other applications in food, health, pigment, and material sectors, among others.

Chemical Profile and Safety Assessment of a Food-Grade Acetogenin-Enriched Antimicrobial Extract from Avocado Seed

Acetogenins are bioactive fatty acid derivatives found in avocado tissues. Their efficacy as antimicrobials has been documented and initiated interest to use them as replacements of synthetic food additives. The present work focused on evaluation of multiple analytical methodologies for detection and quantification of organic solids present in a food-grade acetogenin-enriched extract (Avosafe®), and on its safety evaluations using bacterial reverse mutation (AMES) tests and acute oral toxicity to rat assays. Results confirmed chemical structures of two acetogenins as present in Avosafe® (AcO-avocadyne-(0) and AcO-avocadiene B-(3)), and together with seven other previously known compounds, quantified 94.74 ± 5.77% w/w of its solids as acetogenins. Safety evaluations indicated that Avosafe® was non-mutagenic and had an acute median lethal oral dose (LD50) to rats higher than the maximum concentration tested (>2000 mg·kg-1), with no signs of macroscopic abnormalities in organs. Mean body weight and hematological and biochemical parameters were normal after 14 days of a single oral dose of 2000 mg·kg-1. The results advance scientific information on the safety of avocado seed acetogenins and also generate new knowledge on profiles and concentrations of individual acetogenins found in avocado tissues (seed, pulp, and leaves) and in Avosafe®.