Ultrasound-Assisted Maillard Conjugation of Yeast Protein Hydrolysate with Polysaccharides for Encapsulating the Anthocyanins from Aronia.

Valorisation of food by-products, like spent brewer's yeast and fruit pomaces, represents an important strategy for contributing to sustainable food production. The aims of this study were to obtain Maillard conjugates based on spent yeast protein hydrolysate (SYH) with dextran (D) or maltodextrin (MD) by means of ultrasound treatment and to use them for developing encapsulation systems for the anthocyanins from aronia pomace. The ultrasound-assisted Maillard conjugation promoted the increase of antioxidant activity by about 50% compared to conventional heating and SYH, and was not dependent on the polysaccharide type. The ability of the conjugates to act as wall material for encapsulating various biologically active compounds was tested via a freeze-drying method. The retention efficiency ranged between 58.25 ± 0.38%-65.25 ± 2.21%, while encapsulation efficiency varied from 67.09 ± 2.26% to 88.72 ± 0.33%, indicating the strong effect of the carrier material used for encapsulation. The addition of the hydrolysed yeast cell wall played a positive effect on the encapsulation efficiency of anthocyanins when used in combination with the SYH:MD conjugates. On the other hand, the stability of anthocyanins during storage, as well as their bioavailability during gastrointestinal digestion, were higher when using the SYH:D conjugate. The study showed that hydrolysis combined with the ultrasound-assisted Maillard reaction has a great potential for the valorisation of spent brewer's yeast as delivery material for the encapsulation of bioactive compounds.

Bioactive Potential of Carrot-Based Products Enriched with Lactobacillus plantarum.

The primary goal of this study was to generate different kinds of functional products based on carrots that were supplemented with lactic acid bacteria. The fact that carrots (Daucus carota sp.) rank among the most popular vegetables in our country led to the convergence of the research aim. Their abundance of bioactive compounds, primarily polyphenols, flavonoids, and carotenoids, offers numerous health benefits. Among the obtained products, the freeze-dried carrot powder (FDCP) variation presented the highest concentrations of total carotenoids (TCs) and ß-carotene (BC) of 26.977 ± 0.13 mg/g DW and 22.075 ± 0.14 mg/g DW, respectively. The amount of total carotenoids and ß-carotene significantly increased with the addition of the selected lactic acid bacteria (LAB) for most of the samples. In addition, a slight increase in the antioxidant activity compared with the control sample for the FDCP variant, with the highest value of 91.74%, was observed in these functional food products. The content of polyphenolic compounds varied from 0.044 to 0.091 mg/g DW, while the content of total flavonoids varied from 0.03 to 0.66 mg/g DW. The processing method had an impact on the population of L. plantarum that survived, as indicated by the viability of bacterial cells in all the analyzed products. The chromatographic analysis through UHPLC-MS/MS further confirmed the abundance of the bioactive compounds and their corresponding derivatives by revealing 19 different compounds. The digestibility study indicated that carotenoid compounds from carrots followed a rather controlled release. The carrot-based products enriched with Lactobacillus plantarum can be considered newly functional developed products based on their high content of biologically active compounds with beneficial effects upon the human body. Furthermore, these types of products could represent innovative products for every related industry such as the food, pharmaceutical, and cosmeceutical industries, thus converging a new strategy to improve the health of consumers or patients.

Chemical Composition and Antioxidant Profile of Sorghum (Sorghumbicolor (L.) Moench) and Pearl Millet (Pennisetumglaucum (L.) R.Br.) Grains Cultivated in the Far-North Region of Cameroon.

Sorghum and pearl millet are grain crops that can grow in semi-arid climates, with nutritional and bioactive properties superior to those of major cereals such as rice, wheat, and maize. However, these properties vary a lot, depending on the genetic factors, growing conditions, and place of cultivation. Four sorghum and two pearl millet grains cultivars grown in the Far-North region of Cameroon were screened for their chemical composition and antioxidant profile. The proximate and mineral analyses were performed using AOAC standard methods. The antioxidant profile was assayed spectrophotometrically and details on the phenolic compounds were investigated using HPLC. The pearl millet cultivars, especially mouri, showed higher contents of proteins, lipids, ash, calcium, copper, iron, and zinc. The red sorghum specifically exhibited the greatest amounts of total polyphenols (82.22 mg GAE/g DE), total flavonoids (23.82 mg CE/g DE), and total 3-deoxyanthocyanidin (9.06 mg/g DE). The most abundant phenolic compound was gallic acid, while the most frequent were chlorogenic and ferulic acids. The maximum antioxidant activity against DPPH was observed in yellow-pale sorghum (87.71%), followed by red sorghum (81.15%). Among the studied varieties of cereals, mouri pearl millet and red sorghum were the best sources of nutrients and bioactive compounds, respectively. Their consumption should be encouraged to tackle nutrient deficiencies and non-communicable diseases within local populations.

Value-Added Crackers Enriched with Red Onion Skin Anthocyanins Entrapped in Different Combinations of Wall Materials.

The objective of this study was to encapsulate anthocyanins from red onion skins into different biopolymeric matrices as a way to develop powders with multifunctional activities. Two different variants of powders were obtained using a combination of gelation and freeze-drying techniques and characterized by encapsulation efficiency, antioxidant activity, phytochemical content, and color. Stability during storage and the bioavailability of anthocyanins in the in vitro simulated digestion were also examined. Powder V2, with a higher concentration of polysaccharides than V1, allowed a better encapsulation efficiency (90.53 ± 0.29%) and good stability during storage. Both variants had a high content of phytochemicals and antioxidant activity. In vitro investigations proved that an increased polysaccharides concentration offers the best protection for anthocyanins. Thus, a controlled release of the anthocyanins in the intestinal medium was achieved. The powder with the highest encapsulation efficiency was added to crackers, followed by phytochemical characterization to assess its potential added value. The addition of the micro-particles improved the functional characteristics such as antioxidant activity, showing its suitability for the development of bakery products. The attained results may bring implicit benefits to consumers, who can benefit from improved bioactive concentrations in foodstuffs, with significant health benefits.

CO2 Supercritical Fluid Extraction of Oleoresins from Sea Buckthorn Pomace: Evidence of Advanced Bioactive Profile and Selected Functionality.

The processing of sea buckthorn generates a significant amount of pomace, seeds and skin considered valuable sources of health-promoting macromolecules, such as carotenoids, pectin, flavonoids, phytosterols, polyunsaturated fatty acids and tocopherols. In this study, the bioactives from sea buckthorn pomace (SBP) were extracted using supercritical carbon dioxide (SFE-CO2), at different temperatures and pressures, allowing for obtaining four fractions according to separators (S40 and S45). The highest carotenoid content of 396.12 ± 1.02 mg/g D.W. was found in the S40 fraction, at extraction parameters of 35 °C/45 MPa, yielding an antioxidant activity of 32.10 ± 0.17 mMol TEAC/g D.W. The representative carotenoids in the extract were zeaxanthin, ß-carotene and lycopene, whereas all enriched SFE-CO2 extracts contained α-, ß- and δ-tocopherol, with α-tocopherol representing around 82% of all fractions. ß-sitosterol was the major phytosterol in the fractions derived from S45. All fractions contained significant fatty acids, with a predominance of linoleic acid. Remarkably, the enriched extracts showed a significant palmitoleic acid content, ranging from 53 to 65 µg/g. S40 extracts showed a good antibacterial activity against Staphylococcus aureus and Aeromonas hydrophila ATCC 7966, whereas S45 extracts showed a growth inhibition rate of 100% against Aspergillus niger after three days of growth. Our results are valuable, and they allow identifying the different profiles of extracts with many different applications in food, pharmaceutics, nutraceuticals and cosmeceuticals.

Improvement of Quality Properties and Shelf Life Stability of New Formulated Muffins Based on Black Rice.

Effects of partial (50%) and total replacement of wheat flour with black rice flour on the phytochemical, physico-chemical, sensorial, and textural properties of muffins were studied. Partial or total replacement of wheat flour with black rice flour in muffins improved their nutritional and antioxidative properties with a positive effect on microbiological and color stability during the storage period in accelerated conditions. The low gluten muffins had an anthocyanin content of 27.54 ± 2.22 mg cyanidin-3-glucoside (C3G)/100 g dry weight (DW), whereas the gluten free muffins had 46.11 ± 3.91 mg C3G/100 g DW, with significant antioxidant values. Retention of 60% and 64% for anthocyanins and 72% and 80% for antioxidant activity after baking was found. The fracturability and hardness scores increased with the addition of black rice flour, whereas firmness and chewiness increased for gluten free muffins. The confocal analysis revealed a tendency of glucidic components to aggregate, with gathers of small bunches of black rice starch granules comprising anthocyanin. The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.

Antioxidative Capacity of and Contaminant Concentrations in Processed Plum Products Consumed in Romania.

The bioactive compounds (total phenols, anthocyanins, and flavonoids) and antioxidant activity of plum-based products (prunes, jams, and marmalade) were evaluated based on spectrophotometric assays and acrylamide and 5-hydroxymethyl-2-furaldehyde concentrations to determine the quality and safety of these products in the Romanian marketplace. The total polyphenol concentrations in prunes, marmalade, and jams were 0.93 to 5.63 g of gallic acid equivalent per kg of dry matter, and the antioxidant activity was 3.0 to 17.2 mmol/kg. The concentrations of potentially harmful acrylamide in the plum products ranged from the limit of quantitation (<20 µg/kg) to 37.44 µg/kg, and the concentration was higher in prunes (26.66 to 163.72 µg/kg) than in jams. The 5-hydroxymethyl-2-furaldehyde concentrations in plum products were also variable, at 36 to 2,149 mg/kg. These data revealed a very low concentration of acrylamide in thermally processed plum products, and the results for total polyphenols and the antioxidant activity of prunes and plum jams may be relevant for evaluating these products as important sources of bioactive compounds.

Transglutaminase mediated microencapsulation of sea buckthorn supercritical CO2 extract in whey protein isolate and valorization in highly value added food products.

Sea buckthorn carotenoids extracted using CO2 supercritical fluids method were encapsulated within whey proteins isolate by transglutaminase (TG) mediated crosslinking reaction, coacervation and freeze drying. The encapsulation efficiency was 36.23 ±â€¯1.58%, with ß-carotene the major carotenoid present in the powder. The confocal analysis revealed that TG-ase mediated cross-linking reaction enhanced the complexes stability to such a manner that a double microencapsulation was performed. The powder showed an antioxidant activity of 2.16 ±â€¯0.14 mMol Trolox/g DW and an antifungal activity against Penicillium expansum MIUG M11. Four variants of domestic ice creams were obtained, with a total carotenoids content variation of 1.63 ±â€¯0.03 mg/g D.W. in sample with 2% powder and 6.38 ±â€¯0.04 mg/g D.W. in samples with 4% extract, having satisfactory antioxidant activity. The storage stability test showed a decrease in both total carotenoids content and antioxidant activity in all samples during 21 days at -18 °C. A protective effect of microencapsulation was evidenced.

The kinetics of thermal degradation of polyphenolic compounds from elderberry ( Sambucus nigra L.) extract.

This main focus of this study was to evaluate the thermal degradation kinetics and the phytochemical characterization of the elderberries extract. Pelargonidin-3-sophoroside and delphinidin-3-glucoside were identified as the major anthocyanin compounds and catechin hydrate as the major flavonoid compound. In order to further understand the action of the heat treatment on the bioactive compounds from elderberry extract, fluorescence studies were also carried out. In general, heating at temperatures ranging from 100 to 150 ℃ for up to 90 min caused a decrease in fluorescence intensity, simultaneously with significant redshifts in λmax suggesting important molecular changes inside the anthocyanins structure, affecting the antioxidant activity. Increasing the heating time up to 120 min, the elderberry extract peaked at about 88 nm shifted toward higher wavelengths with respect to that of untreated solutions (peak at 442 nm). The kinetics studies of anthocyanins, fluorescence intensity, and antioxidant activity evidenced a decrease of the degradation rate constants with increased temperature while the activation energies for heat-induced fluorescence intensity, monomeric anthocyanins, and antioxidant activity were 39.62 ± 9.60, 49.97 ± 5.61, and 31.04 ± 19.92 kJ/mol, respectively. Our results can be valuable in terms of establishing the appropriate processing and formulation protocols that could lead to a more efficient utilization of these pigments in actual food products and/or nutraceuticals.

Phytochemicals content and antioxidant properties of sea buckthorn (Hippophae rhamnoides L.) as affected by heat treatment - Quantitative spectroscopic and kinetic approaches.

The effect of thermal processing (50-100°C) on the degradation of the phytochemicals in sea buckthorn extract was investigated using chromatographic, fluorescence and FT-IR spectroscopy techniques and degradation kinetics. Heating the sea buckthorn extract resulted in structural changes that led to red- or blue-shifts in maximum emission, depending on temperature and excitation wavelengths. The attenuated total reflectance analysis of the sea buckthorn extract revealed a satisfactory thermostability of compounds at high temperatures. A fractional conversion kinetic model was used to describe the mechanism of degradation in terms of rate and activation energy. Activation energies for total carotenoids, polyphenolic, flavonoids, and antioxidant activity were 8.45±0.93kJ/mol, 2.50±0.66kJ/mol, 22.50±7.26kJ/mol and 15.22±2.75kJ/mol, respectively. The kinetic parameters evidence a higher thermal stability of carotenoids and polyphenols, suggesting higher degradation rates for flavonoids and antioxidant activity. Our results demonstrate that industrial process optimization in terms of time-temperature combinations demands product specific kinetic data.

Thermal stability of the complex formed between carotenoids from sea buckthorn (Hippophae rhamnoides L.) and bovine ß-lactoglobulin.

Sea buckthorn has gained importance as a versatile nutraceutical, due to its high nutritive value in terms of carotenoids content. ß-Lactoglobulin (ß-LG) is a natural carrier for various bioactive compounds. In this study, the effect of thermal treatment in the temperature range of 25 to 100°C for 15min on the complex formed by ß-LG and carotenoids from sea buckthorn was reported, based on fluorescence spectroscopy, molecular docking and molecular dynamics simulation results. Also, the berries extracts were analyzed for their carotenoids content. The chromatographic profile of the sea buckthorn extracts revealed the presence of zeaxanthin and ß-carotene, as major compounds. The Stern-Volmer constants and binding parameters between ß-LG and ß-carotene were estimated based on quenching experiments. When thermally treating the ß-LG-carotenoids mixtures, an increase in intrinsic and extrinsic fluorescence intensity up to 90°C was observed, together with blue-shifts in maximum emission in the lower temperature range and red-shifts at higher temperature. Based on fluorescence spectroscopy results, the unfolding of the protein molecules at high temperature was suggested. Detailed information obtained at atomic level revealed that events taking place in the complex heated at high temperature caused important changes in the ß-carotene binding site, therefore leading to a more thermodynamically stable assembly. This study can be used to understand the changes occurring at molecular level that could help food operators to design new ingredients and functional foods, and to optimize the processing methods in order to obtain healthier food products.

pH and heat induced structural changes of chicken ovalbumin in relation with antigenic properties.

Ovalbumin is the major egg white protein known to induce allergic reactions in humans. A comprehensive evaluation of the structural and antigenicity features of ovalbumin subjected to different pH and heat treatments was performed by combining fluorescence spectroscopic measurements, ELISA and in silico prediction. The intrinsic fluorescence spectra indicated modification of the ovalbumin tertiary structure depending on pH and applied temperature. The heat treatment caused the alteration of ovalbumin structure, which exhibited gradual hydrophobic exposure. The in depths check of ovalbumin molecular model, after performing molecular dynamics simulations, indicated the slight transition toward a typical ß-strand dominant structure with the temperature increase. Moreover the immunoenzymatic test was employed to estimate the effect of the pH and thermal treatment on the stability of ovalbumin epitopes. Only a 5.5% reduction of the residual antigenicity was observed when heat treating the ovalbumin samples at pH 7.0, whereas a significant reduction (over 82%) of the antigenicity was obtained at pH 9.5 and temperatures over 80°C. Both pH and thermal treatment affected the conformation of ovalbumin. The reduced recognition of the modified native ovalbumin by specific antibodies at alkaline pH is most probably a consequence of significant changes in the local conformation of the epitopes.