Microstructural Changes in Vanilla planifolia Beans after Using High-Hydrostatic-Pressure Treatment in the Curing Process.

During vanilla bean curing, the cell arrangement derived from the killing technique applied to start bean ripening is essential to obtain the characteristic aroma and flavor of vanilla. Hence, killing is an important step to release the enzymes and compounds required for vanillin production. In this work, high hydrostatic pressure (HHP) at 100-400 MPa for 5 min, using water at 7 °C as the pressure-transmitting medium, was applied as the killing method, and its effect on the microstructural changes in vanilla beans during different curing cycles (C0-C20) was evaluated and compared with that observed after scalding by using water at 100 °C for 8 s. Microstructural changes in the cross-sectioned beans were analyzed using a stereomicroscope (SM), confocal laser scanning microscopy (CLSM), and environmental scanning electron microscopy (ESEM). The vanilla beans were cross-sectioned and three main sectors were analyzed: the total, annular, and core. The morphometric descriptors, namely, area, Feret's diameter, and circularity, were quantified via digital image analysis (DIA), from which a shrinkage ratio was calculated. The results show that the total area in the beans presented a maximum decrease in the C16 of curing. The core area was most affected by the HHP treatment, mainly at 400 MPa, rather than scalding. CSLM observations revealed the autofluorescence of the compounds inside the beans. In conclusion, the use of microscopy techniques and DIA allowed us to determine the microstructural changes in the HHP-treated pods, which were found to be more numerous than those found in the scalded beans.

Enzymatic Activity and Its Relationships with the Total Phenolic Content and Color Change in the High Hydrostatic Pressure-Assisted Curing of Vanilla Bean (Vanilla planifolia).

Diverse enzymatic reactions taking place after the killing of green vanilla beans are involved in the flavor and color development of the cured beans. The effects of high hydrostatic pressure (HHP) at 50-400 MPa/5 min and blanching as vanilla killing methods were evaluated on the total phenolic content (TPC), polyphenoloxidase (PPO), and peroxidase (POD) activity and the color change at different curing cycles of sweating-drying (C0-C20) of vanilla beans. The rate constants describing the above parameters during the curing cycles were also obtained. The TPC increased from C1 to C6 compared with the untreated green beans after which it started to decrease. The 400 MPa samples showed the highest rate of phenolic increase. Immediately after the killing (C0), the highest increase in PPO activity was observed at 50 MPa (46%), whereas for POD it was at 400 MPa (25%). Both enzymes showed the maximum activity at C1, after which the activity started to decrease. As expected, the L* color parameter decreased during the entire curing for all treatments. An inverse relationship between the rate of TPC decrease and enzymatic activity loss was found, but the relationship with L* was unclear. HHP appears to be an alternative vanilla killing method; nevertheless, more studies are needed to establish its clear advantages over blanching.

Antioxidant and Renin Inhibitory Activities of Peptides from Food Proteins on Hypertension: A Review.

Hypertension is a condition induced by oxidative stress causing an alteration in the endothelium, which increases the risk of suffering from other degenerative diseases. This review compiles the findings on peptides from food proteins with antioxidant and antihypertensive activities. Antihypertensive peptides are mainly focused on renin inhibition. Peptides containing hydrophobic amino acids have antioxidant and renin inhibitory activities, as reported by studies on the biological activity of peptides from various food sources evaluated separately and simultaneously. Peptides from food sources can present multiple biological activities. Moreover, antioxidant peptides have the potential to be evaluated against renin, offering an alternative for hypertension therapy without causing adverse side effects.

Scavenging peptides, antioxidant activity, and hypoglycemic activity of a germinated amaranth (Amaranthus hypochondriacus L.) beverage fermented by Lactiplantibacillus plantarum.

Amaranthus hypochondriacus L. is a pseudocereal with nutritional properties. Some bioactive peptides have been identified from amaranth protein isolates. The metabolic reactions developed during seed germination have produced different functional foods. The present research aimed to develop a non-dairy germinated amaranth-based functional beverage fermented by Lactiplantibacillus plantarum (LP) strain using Lacticaseibacillus casei Shirota (LCS) as control. The content of betalains (BT), total phenolic compounds (TFC), antioxidant capacity (DPPH, ABTS, FRAP), color changes, and scavenging bioactive peptides were determined. BT in the original base was significantly increased after fermentation by LP and LCS (from 1.276 ± 0.030 to 2.732 ± 0.196 and 1.904 ± 0.760 mg/100 ml, respectively). TFC increased after fermentation; however, no significant differences were found between the two strains (p > .05). The fermentation did not decrease the antioxidant content of the germinated amaranth base. However, a slight increase in the antioxidant capacity was found by DPPH, ABTS, and FRAP in the beverage fermented by LP compared with the LCS one. Moreover, the peptidomic approach suggested 18 peptides with scavenging activity. Thus, a bioactive food product with antioxidant properties was obtained by germination of A. hypochondriacus and its subsequent fermentation by LP. PRACTICAL APPLICATIONS: Non-dairy fermented beverages are novel carriers for probiotics and beneficial metabolites. This research evaluated the antioxidant and hypoglycemic activity of a fermented drink made with amaranth (Amaranthus hypochondriacus) and a potential probiotic strain (Lactiplantibacillus plantarum). The results led to conclude that it is possible to develop functional drinks with potential antioxidant and hypoglycemic activities and provide the biochemical basis for further research and development.

Effect of In Vitro Digestion on the Antioxidant Compounds and Antioxidant Capacity of 12 Plum (Spondias purpurea L.) Ecotypes.

Spondias purpurea L. plum is a source of antioxidant compounds. Nevertheless, once they are consumed and go through the digestive system, these compounds may undergo changes that modify their bioaccessibility. This study aimed to evaluate the effect of in vitro gastrointestinal digestion on the total content of carotenoids (TCC), ascorbic acid (AA), phenolic compounds (TPC), flavonoids (TFC), anthocyanins (TAC), and antioxidant capacity (ABTS, DPPH) of 12 plum Spondias purpurea L. ecotypes. The plum samples were subjected to the InfoGest in vitro digestion model. TCC, AA, TPC, TFC, TAC, ABTS, and DPPH were significantly different (p ≤ 0.05) in each in vitro digestion stage. The gastric stage released the highest content of AA (64.04-78.66%) and TAC (128.45-280.50%), whereas the intestinal stage released the highest content of TCC (11.31-34.20%), TPC (68.61-95.36%), and TFC (72.76-95.57%). Carotenoids were not identified in the gastric stage whilst anthocyanins were lost at the end of the intestinal digestion. At the gastric stage, AA presented a positive and high correlation with ABTS (r: 0.83) and DPPH (r: 0.84), while, in the intestinal stage, TPC and TFC presented positive and high correlation with ABTS (r ≥ 0.8) and DPPH (r ≥ 0.8), respectively.

Extraction and Microencapsulation of Bioactive Compounds from Muicle (Justicia spicigera) and Their Use in the Formulation of Functional Foods.

Bioactive compounds (BC) present in muicle leaves were extracted using the best extraction conditions obtained with a Box-Behnken experimental design, extracting 95% of BC. Microencapsulation of muicle BC was carried out by spray drying using DE10 maltodextrin (MD) and soy protein isolate (SPI) as encapsulating agents. The best conditions for the ethanolic extraction of BC from muicle were 30 °C, 40% aqueous ethanol, and one extraction for 1 h. The best spray drying encapsulating conditions for BC and antioxidant capacity (AC) using MD as an encapsulating agent were: 160-80 °C and 10% MD in the feeding solution, and for SPI: 180-70 °C and 5% SPI in the feeding solution. Microcapsules were added to yogurt and a sensory evaluation and retention of BC during 15-day storage at 4 °C was performed. Sensory evaluation showed that yogurt with added MD microcapsules had better acceptance than that with SPI microcapsules. Based on this, a jelly with added muicle MD microcapsules was also prepared which obtained better acceptance by the judges. At the end of the storage period, yogurt with SPI microcapsules showed better retention of BC and AC than yogurts with MD microcapsules; however, products with MD microcapsules had better acceptance.

An 1H NMR-based metabolomic approach to compare the chemical profiling of retail samples of ground roasted and instant coffees.

The present non-targeted 1H NMR-based fingerprinting approach along with multivariate analysis established differences between representative aqueous extracts of commercial ground roasted coffee (GRC) and instant (soluble) coffee (IC) samples. The latter were prepared either by spray drying or freeze drying. When comparing a total of 33 compounds between GRC and IC, the latter product contained a remarkable increase in 5-(hydroxymethyl)furfural and carbohydrates, as well as a clear decrease in trigonelline, N-methylpyridinium, caffeine, caffeoylquinic acids and 2-furylmethanol. Furthermore, the current protocol was able to detect the subtle chemical differences between spray-dried and freeze-dried IC. The aforementioned metabolites could serve as target molecules in the attempt to preserve, as much as possible, the organoleptic and nutraceutical properties of GRC during the industrial drying processes used in the production of the two commercial types of IC.

Influence of shape and dispersion media of titanium dioxide nanostructures on microvessel network and ossification.

Titanium dioxide nanoparticles (TiO2 NPs) production has been used for pigment, food and cosmetic industry and more recently, shaped as belts for treatment of contaminated water, self-cleaning windows and biomedical applications. However, the toxicological data have demonstrated that TiO2 NPs inhalation induce inflammation in in vivo models and in vitro exposure leads to cytotoxicity and DNA damage. Dermal exposure has limited adverse effects and the possible risks for implants used for tissue regeneration is still under research. Then, it has been difficult to establish a straight statement about TiO2 NPs toxicity since route of exposure and shapes of nanoparticles play an important role in the effects. In this study we aimed to investigate the effect of three different types of TiO2 NPs (industrial, food-grade and belts) dispersed in fetal bovine serum (FBS) and saline solution (SS) on microvessel network, angiogenesis gene expression and femur ossification using a chick embryo model after an acute exposure of NPs on the day 7 after eggs fertilization. Microvascular density of chorioallantoic membrane (CAM) was analyzed after 7days of NPs injection and vehicles induced biological effects per se. NPs dispersed in FBS or SS have slight differences in microvascular density, mainly opposite effect on angiogenesis gene expression and no effects on femur ossification for NPs dispersed in SS. Interestingly, NPs shaped as belts dramatically prevented the alterations in ossification induced by FBS used as vehicle.

Hypocholesterolemic and Anticarcinogenic Effect of Vicia faba Protein Hydrolyzates.

In recent years, the consumption of vegetal-source proteins has been studied to determine their preventing effect on the development of several chronic diseases. The initial purpose of this report was to determine the effect of a hypercholesterolemic diet (HCD) given to mice, alone or with azoxymethane (AOM), on various obesity biochemical biomarkers, as well as on the induction of colon aberrant crypts (aberrant crypt foci; ACF). At the end of the 5-week assay, animals fed the HCD showed alterations in the level of total cholesterol, high- and low-density lipoproteins, and in the Atherogenic Index; besides, a significant elevation was observed in the number of ACF. Our second aim was to examine the effect of a Faba Protein Hydrolyzate (FPH) on mice fed the HCD. We first obtained protein hydrolyzates from the seeds of Vicia faba, determined the in vitro antioxidant potential with two tests, and, subsequently, evaluated the effect on obesity biomarkers and on the number of ACF. In the first case, we found that, generally, the best protective effect was obtained with the low dose of FPH (10 mg/kg) administered to animals fed the HCD, and injected AOM. With respect to the number of ACF, we observed that this dose was more effective, inhibiting such lesions to almost the level determined for the normocholesterolemic diet (NCD). Therefore, our results demonstrated the relevance of a HCD to develop anomalies in obesity biomarkers in mouse, as well as to increase the number of precarcinogenic lesions. Our results also showed a protective response with the administration of FPH, particularly with a specific dose, suggesting the need for extending research on the matter by widening the spectra of doses, in order to clearly define its potential to counteract the damage induced by the HCD, as well as to confirm if antioxidation in mice was involved in such an effect.

Biochemical and molecular analysis of some commercial samples of chilli peppers from Mexico.

The genus Capsicum provides antioxidant compounds, such as phenolics and carotenoids, into the diet. In Mexico, there is a wide diversity of species and varieties of chilli peppers, a fruit which has local cultural and gastronomic importance. In the present study, the relationship of the carotenoid and phenolic profiles with the RAPD fingerprint of three different commercial cultivars of chilli peppers of seven regions of Mexico was investigated. Through RAPD, the species of chilli were differentiated by means of different primers (OPE-18, MFG-17, MFG-18, C51, and C52). The genetic distance found with OPE 18 was in the order of 2.6. The observed differences were maintained when the chromatographic profile of carotenoids, and the molecular markers were analyzed, which suggest a close relationship between carotenoids and the genetic profile. While the chromatographic profile of phenols and the molecular markers were unable to differentiate between genotypes of chilli peppers. In addition, by using infrared spectroscopy and statistical PCA, differences explained by geographic origin were found. Thus, this method could be an alternative for identification of chilli species with respect to their geographic origin.

Water droplet spreading and recoiling upon contact with thick-compact maltodextrin agglomerates.

BACKGROUND: The food and pharmaceutical industries handle a number of compounds in the form of agglomerates which must be put into contact with water for rehydration purposes. In this work, liquid-solid interaction between water and maltodextrin thick-compact agglomerates was studied at different constituent particle sizes for two compression forces (75 and 225 MPa). RESULTS: Rapid droplet spreading was observed which was similar in radius to the expected one for ideal, flat surfaces. Contact angle determinations reported oscillations of this parameter throughout the experiments, being indicative of droplet recoiling on top of the agglomerate. Recoiling was more frequent in samples obtained at 225 MPa for agglomerate formation. Agglomerates obtained at 75 MPa exhibited more penetration of the water. Competition between dissolution of maltodextrin and penetration of the water was, probably, the main mechanism involved in droplet recoiling. Micrographs of the wetting marks were characterized by means of image analysis and the measurements suggested more symmetry of the wetting mark at higher compression force. CONCLUSION: Differences found in the evaluated parameters for agglomerates were mainly due to compaction force used. No significant effect of particle size in recoiling, penetration of water into the agglomerate, surface texture and symmetry was observed.