Avocado fruit contains lipid derivatives with antimicrobial properties called acetogenins. In this study, antimicrobial spectrum of purified acetogenins was characterized. Additionally, eight Grampositive bacteria were exposed to commercial food preservatives (Nisaplin® and Mirenat®) for comparison. Acetogenins were also added to a food system containing meat, inoculated with Listeria monocytogenes and stored at 20°C and 4°C. Avocado seed extract (Avosafe®) contained 71.3% w/w total acetogenins, its main components were AcO-avocadene and persenone A (22.05 ± 1.84 and 20.14 ± 1.40% w/w, respectively). Avosafe® (15 µg disc −1) inhibited Gram-positive bacteria, with higher efficacy towards spore-formers (Clostridium sporogenes, C. perfringens, Bacillus subtilis, and Alicyclobacillus acidocaldarius). Acetogenins' inhibition zones were 2-4 times higher compared to Nisaplin® and Mirenat® for Gram-positive bacteria, except for Staphylococcus aureus. During refrigerated storage (4°C, 72 d), Avosafe® inhibited L. monocytogenes completely; decreasing initial 3-log inoculum to undetectable levels within 3 h, and maintaining the effect to completion. Acetogeninas Aisladas de Semilla de Aguacate: Espectro Antimicrobiano y Completa Inhibición del Crecimiento de Listeria monocytogenes en una Matriz Alimenticia Refrigerada RESUMEN El aguacate contiene derivados lipídicos con propiedades antimicrobianas llamadas acetogeninas. En este estudio se caracterizó el espectro antimicrobiano de acetogeninas purificadas de la semilla del fruto. Las propiedades antimicrobianas de las acetogeninas se compararon con conservadors comerciales (Nisaplin® y Mirenat®) utilizando un panel de ocho bacterias Gram positivas. Las acetogeninas también se incorporaron en la matriz de un alimento que contenía carne, el cual se inoculó con Listeria monocytogenes y se almacenó a 20 y 4°C. La concentración de acetogeninas totales en el extracto de semilla de aguacate (Avosafe®) fue de 71.3 % p/p, de las cuales AcO-avocadeno y persenona A (22.05 ± 1.84 y 20.14 ± 1.40% p/p, respectivamente) fueron los componentes principales. Avosafe® (15 µg disco-1) inhibió a las bacterias Gram positivas, mostrando una mayor eficacia contra aquellas formadoras de esporas (Clostridium sporogenes, C. perfringens, Bacillus subtilis y Alicyclobacillus acidocaldarius). Las zonas de inhibición del crecimiento de las bacterias Gram positivas producidas por las acetogeninas fueron 2-4 veces mayores que las de Nisaplin® y Mirenat®, con excepción de Staphylococcus aureus. Durante el almacenamiento en condiciones de refrigeración (4°C, 72 d), Avosafe® inhibió completamente a L. monocytogenes; el inóculo inicial disminuyó en 3-log hasta niveles indetectables después de 3 h, y el efecto inhibitorio se mantuvo hasta la finalización del estudio.

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®.

Trends in new food products focus on low-carbohydrate ingredients rich in healthy fats, proteins, and micronutrients; thus, avocado has gained worldwide attention. This study aimed to use predictive modeling to identify the potential sensory drivers of liking for avocado pulp by evaluating acceptability scores and sensory descriptive profiles of two commercial and five non-commercial cultivars. Macronutrient composition, instrumental texture, and color were also characterized. Trained panelists performed a descriptive profile of nineteen sensory attributes. Affective data from frequent avocado adult consumers (n = 116) were collected for predictive modeling of an external preference map (R2 = 0.98), which provided insight into sensory descriptors that drove preference for particular avocado pulps. The descriptive map explained 67.6% of the variance in sensory profiles. Most accepted pulps were from Hass and Colin V-33; the latter had sweet and green flavor notes. Descriptive flavor attributes related to liking were global impact, oily, and creamy. Sensory drivers of texture liking included creamy/oily, lipid residue, firmness, and cohesiveness. Instrumental stickiness was disliked and inversely correlated to dry-matter and lipids (r = −0.87 and −0.79, respectively). Color differences (∆Eab*) also contributed to dislike. Sensory-guided selection of avocado fruits and ingredients can develop products with high acceptability in breeding and industrialization strategies.

Anticlostridial activity of acetogenins from avocado seed was further characterised, and their stability and effectiveness under food processing conditions, and in a model food system, studied for the first time. Isolated AcO-avocadenyne (1) and AcO-avocadene (2) showed anticlostridial potential, particularly the latter molecule. Enriched acetogenins extracts, obtained at laboratory scale (EAE) and semi-commercially (Avosafe Ò ), presented similar MIC values (3.9-9.8 ppm) and a bacteriostatic effect. Extracts bioactivity showed resistance to heat (≤120°C), high hydrostatic pressure (HHP; 300-600 MPa, 3-6 min, 25°C) and salt (≤3% w/v). In addition, the extract was most stable at pH ≥ 7.0 and potency against endospores increased after HHP treatment and exposure to pH 9.5, suggesting a positive effect on solubility or structure of particular acetogenins. In a model food system processed by HHP, acetogenins were retained; however, initial quantities gradually declined by 63% and 32% at 25 and 4°C, respectively, at the end of the storage period (42 days). Most stable molecules (persediene (4) > persenones > AcO-avocadene (2)) possess a keto or trans-enone group at C-4 in the aliphatic chain, which could support hydrogen donation to surrounding carbon atoms and confer antioxidant activity. Active endospores were completely inhibited by 5000 ppm Avosafe Ò in the model food system (37°C, 72 h) and lower concentrations (500-1000 ppm) resulted in 1-2 log reduction of a 3 log inoculum target. Efficacy information generated in the present work is considered crucial to improve scientific knowledge on spore inhibition properties of avocado acetogenins.

Some chemical compounds, especially alcohol, sugars, and alkaloids such as hordenine, have been reported as elicitors of different emotional responses. This preliminary study was based on six commercial beers selected according to their fermentation type, with two beers of each type (spontaneous, bottom, and top). Chemometry and sensory analysis were performed for all samples to determine relationships and patterns between chemical composition and emotional responses from consumers. The results showed that sweeter samples were associated with higher perceived liking by consumers and positive emotions, which corresponded to spontaneous fermentation beers. There was high correlation (R = 0.91; R2 = 0.83) between hordenine and alcohol content. Beers presenting higher concentrations of both, and higher bitterness, were related to negative emotions. Further studies should be conducted, giving more time for emotional response analysis between beer samples, and comparing alcoholic and non-alcoholic beers with similar styles, to separate the effects of alcohol and hordenine. This preliminary study was a first attempt to associate beer compounds with the emotional responses of consumers using non-invasive biometrics.