Tecnologías emergentes, alimentación y salud

In this study, we aimed to isolate and phenotypically characterize non-Saccharomyces yeast strains (NSYSs) from the skin of aromatic (Italy) and non-aromatic (Negra Criolla) grapes from vineyards in Moquegua, Peru, typically used for the production of pisco. Our second objective was to characterize the volatile compounds and sensory attributes of pisco made from these grapes. Pichia terricola (56%), Metschnikowia pulcherrima (31%), and Naganishia vaughanmartiniae (13%) were the main NSYSs isolated from the skin of aromatic Italy grapes and identified; meanwhile, Vishniacozyma carnescens (50%), Vishniacozyma heimaeyensis (30%), and Aureobasidium pullulans (20%) were identified on the skin of the non-aromatic Negra Criolla grapes. These NSYSs showed different capacities in terms of carbohydrate fermentation, polygalacturonase activity, ethanol tolerance, sulphite production, and nitrogen consumption. Moreover, the pisco resulting from these varieties of grape had different volatile profiles. Terpene alcohols such as citronellol, geraniol, linalool, and nerol were found in pisco made from Italy grapes, while higher contents of 2-phenylacetate and ethyl esters were found in Negra Criolla Pisco. Intermediate levels of both 1-hexanol and bencyl alcohol were also found in all the pisco. Sensory analysis performed by a trained pisco tasting panel showed that citric, floral, alcohol, and syrup descriptors were more marked in Italy Pisco, while nuts, syrup, alcohol, and floral were the most intense attributes of Negra Criolla Pisco. These results will contribute to determining the potential of indigenous grape yeasts from the Moquegua region as fermentation starters to improve the typical sensory qualities of the pisco produced in this region, which deserves further study.

Avocado oils (AO) from Hass and Fuerte varieties were extracted by supercritical CO₂ (scCO₂) at 40 and 80 °C (400 bar). The yields of the extraction ranged from 36 % to 38 % and AO extraction using scCO₂ showed a good fit to the logistic model. Physicochemical, bioactive compounds, fatty acid composition, antioxidant capacity and oxidative stability of the oil were influenced by scCO₂ extraction. Compared to commercial product extracted by cold pressing, the AO extracted with scCO₂ showed a lower total phenolic content, except for that extracted from the Fuerte variety at 80 °C, as well as higher total carotenoid and chlorophyll contents, unsaturated/saturate fatty acid ratio and antioxidant capacity in that extracted at 80 °C. However, initiation and propagation kinetic parameters, estimated at the first time using accelerated Oxitest system, showed that AO obtained by scCO₂ is more susceptible to lipid oxidation.

Cereals (CE) and pseudocereals (PSCE) play a pivotal role in nourishing the human population. Low-frequency ultrasound (LFUS) modifies the structure of CE and PSCE macromolecules such as starch and proteins, often improving their technological, functional and bioactive properties. Hence, it is employed for enhancing the traditional processes utilized for the preparation of CE- and PSCE-based foods as well as for the upcycling of their by-products. We report recent advances in LFUS treatments for hydration, germination, extraction of bioactive compounds from by-products, and fortification of CEs and PSCE, including kinetic modelling and underlying action mechanisms. Meta-analyses of LFUS influence on compounds extraction and starch gelatinization are also presented. LFUS enhances hydration rate and time lag phase of CE and PSCE, essential for germination, extraction, fermentation and cooking. The germination is improved by increasing hydration, releasing promoters and eliminating inhibitors. Furthermore, LFUS boosts the extraction of phenolic compounds, polysaccharides and other food components; modifies starch structure, affecting pasting properties; causes partial denaturation of proteins, improving their interfacial properties and their peptides availability. Overall, LFUS has an outstanding potential to improve transformation processes and functionalities of CE and PSCE.

With the growing of consumer’s demand for products ready to eat that can be elaborated with greener technologies without affecting to their organoleptic characteristics, the application of ultrasound combined with microwaves has been widely studied on food preservation treatments (drying, frying), extraction of high-value added compounds and enzymatic hydrolysis of proteins. This review presents a complete picture of current knowledge on the ultrasound combined with microwaves including the mechanisms, influencing factors, advantages and drawbacks, emphasising in several synergistic effects observed in different processes of strong importance in the food industry. Recent research has shown that this hybrid technology could not only minimise the disadvantages of power US for drying and frying but also improve the product quality and the efficiency of both cooking processes by lowering the energy consumption. Regarding extraction, current studies have corroborated that the combined method presents higher yields in less time, in comparison with those in the respective ultrasound and microwave separately. Additionally, recent results have indicated that the bioactive compounds extracted by this combined technology exhibit promising antitumor activities as well as antioxidant and hepatoprotective effects. Remarkably, this hybrid technology has been shown as a good pre-treatment since the structural changes that are produced in the molecules facilitate the subsequent action of enzymes. However, the combination of these techniques still requires a proper design to develop and optimized conditions are required to make a scale process, and it may lead to a major step concerning a sustainable development and utilization of bioactive compounds from natural products in real life.

The aim of this study was to predict the total antioxidant capacity (TAC) of altiplano colored quinoa using visible and near-infrared (Vis-NIR) spectral data and chemometrics. In colored quinoa, at least part of the phenolic compounds are included in the non-extractable fraction and therefore the TAC should be measured by a non-conventional QUick, Easy, New, CHEap and Reproducible procedure (QUENCHER). In this work, QUENCHER using 2,2-diphenyl-1-picrylhydrazyl (DPPH) returned a value 1.03–7.03 times higher than the extractable antioxidant capacity, and it represented 2.8%–85.8% of the TAC of altiplano colored quinoa. We applied partial least squares regression and ten-fold cross-validation to the raw and pre-processed NIR spectra for the calibration and validation of models, to predict the TAC of altiplano colored quinoa. The best model was obtained for whole quinoa seeds as opposed to ground samples (calibration: R² = 0.97, RSME = 2.9; validation: R² = 0.73, RSME = 8.6) using Savitzky-Golay smoothing, the D-trend method and multiplicative scatter correction procedures. The QUENCHER-DPPH result was also positively correlated with extractable antioxidant capacity (EAC-DPPH), total free phenolics, total betalain content and L values (p ≤ 0.001). Therefore, we demonstrate that the TAC of colored quinoa seeds, including both non-extractable and extractable antioxidants, can be predicted by Vis-NIR spectra coupled to chemometrics.

Currently there is a growing interest from the food industry in obtaining inulin for its possible use in the elaboration of functional foods. A set of optimum extraction conditions was developed for the recovery of inulin plus fructo-oligosaccharides (FOS) from several common inulin-containing plant sources, like chicory roots (Cichorium intybus L.) and Jerusalem artichoke tubers (Helianthus tuberosus L.), as well as from novel sources like globe artichoke inflorescence (Cynara cardunculus L.) and its by-product. Optimal conditions for temperature (60−80 °C), time (20−60 min) and solvent to solid ratio (10−40 mL/g) were estimated in order to maximize inulin plus FOS extraction by using response surface methodology (RSM) with a Box-Behnken design. Inulin plus FOS were estimated colorimetrically by difference between total carbohydrate and reducing sugar contents for the optimization. Moreover, the profile of inulin and low molecular weight carbohydrates was studied in optimized plant extracts by HPLC. Inulin in raw samples and optimal extracts were further characterized by Fourier Transformed Infrared spectroscopy. According to response surface methodology model, optimal conditions for inulin plus FOS extraction depended on plant source and were achieved at a solvent to solid ratio of 27.8–37.4 mL/g, from 62−80 °C and a variable time of 22−60 min. The highest inulin plus FOS contents were achieved in chicory root (70.5 g/100 g dry weight) and Jerusalem artichoke tuber (81.1 g/100 g dry weight), and the lowest ones were attained in globe artichoke by-product (4.2 g/100 g). Nevertheless, its high availability and low cost would support this novel globe artichoke by-product as an alternative and valuable source of inulin and FOS for the food industry. At the same time their reuse as potential prebiotic ingredients would contribute to the circular economy.

Kiwicha (Amaranthus caudatus) is a gluten-free pseudocereal, regarded as a good source of high-quality protein and fiber. The use of whole flours is of interest for obtaining healthy extruded snacks but the Sectional Expansion Index (SEI) can decrease. The aims of the study were to: a) evaluate the effect of initial moisture and extrusion temperature using a face-centered central composite design on the physical-chemical properties of kiwicha whole flour such as water activity, SEI, density, water absorption index, Water Solubility Index (WSI), color, texture (hardness and shear strength), gelatinization degree, pasting properties, thermal properties, total phenolic (TP) and antioxidant capacity by DPPH (AC-DPPH) and ABTS (AC-ABTS) and b) optimize the extrusion cooking using response surface methodology maximizing SEI, WSI, TP, AC-DPPH and AC-ABTS. The extrusion cooking parameters influenced on physical-chemical properties of extruded kiwicha. The optimal condition was extrusion temperature of 190 °C and 14% initial moisture and extrudates showed 7.17 SEI, 61.5% WSI, 101.2 μmol trolox/g AC-DPPH, 364.2 μmol trolox/g AC-ABTS and 34.5 mg GAE/100 g TP.

The aim of this study was to develop and validate a microtiter macro lens-coupled smartphone (MCS) assay for the quantitation of the total saponins in quinoa based on foam measurement. The 96-well micro plate with a black bottom and an inclination angle = 12.102° of macro lens-coupled smartphone allows to acquire images with a high resolution. The foam stability, a critical aspect for the MCS assay, was significantly improved by the inclusion of a chelating agent (EDTA 50 mmol L⁻¹) and bovine serum albumin (0.5 mg mL⁻¹). The MCS assay was linear within the range of 9.039–180.773 × 10⁻⁴ mg mL⁻¹ of saponin (R² = 0.9929), using the integrated density/area as a foam measurement (Y) and the logarithm of saponin concentration (X) (Y = 372.1 + 104.2LogX). The MCS assay was 50-folds more sensitive than afrosimetric assay -AA- with LOD = 3.168 × 10⁻⁴ mg mL⁻¹ and LOQ = 4.784 × 10⁻⁴ mg mL⁻¹. MCS assay was more reproducible (relative standard deviation (RSD) = 0.632–9.646%) than AA (RSD = 3.44–44.04%). The correlation analysis, Bland-Altman analysis and Passing-Bablok regression showed good agreement between total saponin content in quinoa as measured by the MCS assay and AA. Based on the green analytical procedure index, MCS assay can be considered as a green procedure.

Quinilla seeds (QS) are a potential source of little-known bioactive compounds with high biological values. This work evaluated the supercritical fluid extraction (SFE) of bioactive compounds from QS for the first time, evidencing the relations between pressure and temperature to the extract yield and composition. Pressures from 15 to 35 MPa and temperatures from 313 to 333 K were tested, and the process was modeled based on the principle of mass conservation. The highest SFE yield was 20.0 g extract/100 g QS, achieved at 35 MPa and 313 K. Close values were obtained at 25 MPa-313 K and 35 MPa-323 K. The composition of the extracts varied with the operating conditions, and the three main compounds presented in all extract were squalene, phenol, 2,4-bis(1,1-dimethylethyl)-, and n-Hexadecanoic acid. The SFE extracts of QS present potential applications in the cosmetic and pharmacological industry that require further study. The proposed mathematical model was in excellent agreement with the experimental data, and it was effectively employed to estimate the SFE yield for large-scale SFE plants.