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^®.

Formaldehyde is a highly reactive compound that participates in multiple spontaneous reactions, but these are mostly deleterious and damage cellular components. In contrast, the spontaneous condensation of formaldehyde with tetrahydrofolate (THF) has been proposed to contribute to the assimilation of this intermediate during growth on C₁ carbon sources such as methanol. However, the in vivo rate of this condensation reaction is unknown and its possible contribution to growth remains elusive. Here, we used microbial platforms to assess the rate of this condensation in the cellular environment. We constructed Escherichia coli strains lacking the enzymes that naturally produce 5,10-methylene-THF. These strains were able to grow on minimal medium only when equipped with a sarcosine (N-methyl-glycine) oxidation pathway that sustained a high cellular concentration of formaldehyde, which spontaneously reacts with THF to produce 5,10-methylene-THF. We used flux balance analysis to derive the rate of the spontaneous condensation from the observed growth rate. According to this, we calculated that a microorganism obtaining its entire biomass via the spontaneous condensation of formaldehyde with THF would have a doubling time of more than three weeks. Hence, this spontaneous reaction is unlikely to serve as an effective route for formaldehyde assimilation.

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.

Biofortification of folates in staple crops is an important strategy to help eradicate human folate deficiencies. Folate biofortification using genetic engineering has shown great success in rice grain, tomato fruit, lettuce, and potato tuber. However, consumers’ skepticism, juridical hurdles, and lack of economic model have prevented the widespread adoption of nutritionally-enhanced genetically-engineered (GE) food crops. Meanwhile, little effort has been made to biofortify food crops with folate by breeding. Previously we reported >10-fold variation in folate content in potato genotypes. To facilitate breeding for enhanced folate content, we attempted to identify genes that control folate content in potato tuber. For this, we analyzed the expression of folate biosynthesis and salvage genes in low- and high-folate potato genotypes. First, RNA-Seq analysis showed that, amongst all folate biosynthesis and salvage genes analyzed, only one gene, which encodes γ-glutamyl hydrolase 1 (GGH1), was consistently expressed at higher levels in high- compared to low-folate segregants of a Solanum boliviense Dunal accession. Second, quantitative PCR showed that GGH1 transcript levels were higher in high- compared to low-folate segregants for seven out of eight pairs of folate segregants analyzed. These results suggest that GGH1 gene expression is an indicator of folate content in potato tubers.

Wounding induces phenolic biosynthesis in broccoli. However, there is scarce information about the physiological and molecular mechanisms governing this stress response. In the present study, a chemical-genetics approach was used to elucidate the role of reactive oxygen species (ROS), jasmonic acid (JA), and ethylene (ET) as stress-signaling molecules in the wound-induced phenolic biosynthesis in broccoli. Wounding activated the biosynthesis of ET and JA. Likewise, the wound-induced biosynthesis of ET and JA was regulated by ROS. JA activated primary metabolism, whereas the three signaling molecules activated phenylpropanoid metabolism. The signaling molecules inhibited the wound-induced activation of the hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) gene, which is involved in caffeoylquinic acids biosynthesis, and the main phenolics accumulated in wounded broccoli, suggesting that an alternative caffeoylquinic biosynthesis pathway is activated in the tissue due to wounding. ROS mediated the biosynthesis of most individual phenolic compounds evaluated. In conclusion, ROS, ET, and JA are essential in activating broccoli’s primary and secondary metabolism, resulting in phenolic accumulation.

In this study, the effects of static and multi-pulsed mild-intensity high hydrostatic pressure (HHP) treatments (60 or 100 MPa, ~23 °C) on the extractability and accumulation of phenolics and carotenoids in whole carrots were evaluated. HHP treatments were applied for the time needed to reach the desired pressure (come-up-time, CUT) either as a single pulse or multi-pulse (2P, 3P, and 4P). Likewise, a single sustained treatment (5 min) applied at 60 or 100 MPa was evaluated. Individual carotenoids, free and bound phenolics were quantified after HHP treatment and subsequent storage (48 h, 15 °C). As an immediate HHP response, phenolic extractability increased by 66.65% and 80.77% in carrots treated with 3P 100 MPa and 4P 60 MPa, respectively. After storage, CUT 60 MPa treatment accumulated free (163.05%) and bound (36.95%) phenolics. Regarding carotenoids, total xanthophylls increased by 27.16% after CUT 60 MPa treatment, whereas no changes were observed after storage. Results indicate that HHP processing of whole carrots at mild conditions is a feasible innovative tool to enhance the nutraceutical properties of whole carrots by increasing their free and bound phenolic content while maintaining carotenoid levels. HHP treated carrots can be used as a new functional food or as raw material for the production of food and beverages with enhanced levels of nutraceuticals.