Bio-aerogels: Fabrication, properties and food applications.

Traditional inorganic aerogels sustainability, biodegradability, and environmental safety concerns have driven researchers to find their safe green alternatives. Recently, interest in the application of bio-aerogels has rapidly increased in the food industry due to their unique characteristics such as high specific surface area and porosity, ultralow density, tunable pore size and morphology, and superior properties (physicochemical, mechanical, and functional). Bio-aerogels, a special category of highly porous unique materials, fabricated by the sol-gel method followed by drying processes, comprising three-dimensional networks of interconnected biopolymers (e.g., polysaccharides and proteins) with numerous air-filled pores. The production of bio-aerogels begins with the formation of a homogeneously dispersed precursor solution, followed by gelation and wet gel drying procedures by employing special drying techniques including atmospheric-, freeze-, and supercritical drying. Due to their special properties, bio-aerogels have emerged as sustainable biomaterial for many industrial applications, i.e., encapsulation and controlled delivery, active packaging, heavy metals separation, water and air filtration, oleogels, and biosensors. Bio-aerogels are low-cost, biocompatible, and biodegradable sustainable material that can be used in improving the processing, storage, transportation, and bioavailability of food additives, functional ingredients, and bioactive substances for their health benefits with enhanced shelf-life.

Effect of heat treatment on phenolic composition and radical scavenging activity of olive leaf extract at different pH conditions: a spectroscopic and kinetic study.

BACKGROUND: The present study focused on the effect of isothermal treatment (5-90 °C) and pH (2.0-6.0) of aqueous olive leaf phenolic extract solutions on the kinetics of degradation of single and total phenolic compounds and radical scavenging activity, with the objective of predicting and optimizing the thermal treatments in foods enriched with olive leaf extracts. RESULTS: The major compound, oleuropein, showed higher degradation at low pH 2.0 and temperature-dependent reaction rates, which fitted well a first-order kinetic model, with an estimated activation energy of 98.03 ± 0.08 kJ mol-1 . Oleuropein hydrolysis resulted in a zero-order increase in hydroxytyrosol concentration at same pH (Ea  = 71.59 ± 1.5 kJ mol-1 ), whereas a 100-fold slower degradation rate was observed at higher pH. Verbascoside was only degraded at pH 6.0, also following first-order kinetics. These changes in oleuropein and hydroxytyrosol concentrations led to significant changes in fluorescence maximum intensities centered around 315 and 360 nm and in the 425-500 nm spectral zone for samples at pH 6.0, which could be associated with verbacoside degradation. Conversely, analysis of total phenolic content and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity showed little changes, indicating a rather constant overall reducing capacity of the resulting pool of compounds after thermal treatments. CONCLUSION: The present study can contribute to the knowledge related to oleuropein and phenolic fraction degradation as a result of matrix (pH) and processing. The kinetic parameters obtained could be applied for predicting and optimizing the thermal treatments in foods and drinks enriched with olive leaf extracts. © 2022 Society of Chemical Industry.

Hazelnut Shells as Source of Active Ingredients: Extracts Preparation and Characterization.

Hazelnut shells represent a waste material (about 42% of the total biomass) deriving from hazelnut harvest. These are mainly used as a heating source; however, they represent an interesting source of polyphenols useful in health field. The impact on phenolic profile and concentrations of hazelnut shell extracts obtained by three extraction methods (maceration, ultrasonic bath, and high-power ultrasonic), as well as temperature, extraction time, and preventive maceration, was studied. The prepared extracts were characterized in terms of chemical composition, antioxidant and antimicrobial activities. Eighteen different phenolic compounds were identified and quantified by chemical analysis and gallic acid was the most abundant in all the extracts analyzed. Other relevant compounds were chlorogenic acid, protocatechuic acid and catechin. Preventive maceration had a positive effect on the extraction of different types of compounds regardless of the method performed. Application of the high-power ultrasonic method had different effects, either positive or negative, depending on the type of compound and extraction time. All the prepared extracts showed antioxidant activity especially those prepared by maceration, and many of them were able to inhibit the growth of both B. subtilis and B. cereus.

Factors affecting flavor perception in space: Does the spacecraft environment influence food intake by astronauts?

The intention to send a crewed mission to Mars involves a huge amount of planning to ensure a safe and successful mission. Providing adequate amounts of food for the crew is a major task, but 20 years of feeding astronauts on the International Space Station (ISS) have resulted in a good knowledge base. A crucial observation from the ISS is that astronauts typically consume only 80% of their daily calorie requirements when in space. This is despite daily exercise regimes that keep energy usage at very similar levels to those found on Earth. This calorie deficit seems to have little effect on astronauts who spend up to 12 months on the ISS, but given that a mission to Mars would take 30 to 36 months to complete, there is concern that a calorie deficit over this period may lead to adverse effects in crew members. The key question is why astronauts undereat when they have a supply of food designed to fully deliver their nutritional needs. This review focuses on evidence from astronauts that foods taste different in space, compared to on Earth. The underlying hypothesis is that conditions in space may change the perceived flavor of the food, and this flavor change may, in turn, lead to underconsumption by astronauts. The key areas investigated in this review for their potential impact on food intake are the effects of food shelf life, physiological changes, noise, air and water quality on the perception of food flavor, as well as the link between food flavor and food intake.

From by-product to food ingredient: evaluation of compositional and technological properties of olive-leaf phenolic extracts.

BACKGROUND: Most olive by-products, like olive leaves, are still undervalued despite their strong potential as a source of healthy and functional components. To exploit their potential use as active ingredients in complex food systems, it is of primary importance the knowledge of their composition and technological functionality which represented the objective of this work. RESULTS: Phenolic extracts from olive leaves, obtained by extraction with pure water (Eth0) and two different water-ethanol solutions (Eth30, Eth70), were characterized for their composition and technological properties such as water- / oil- holding ability, air/water surface activity, and emulsifying capacity at pH 4.5 and 7. Their chemical stability over time, at constant temperature, was also investigated. The technological properties were affected by extraction media and pH. Phenolic extracts displayed significant surface activity, showing dose-dependent behavior. Surface properties were affected by pH and this result was confirmed by the emulsifying capacity. The extracts showed good oil-holding capacity but limited water-binding capacity. Eth70 showed the highest chemical stability, which was confirmed by the rate parameters obtained by modeling data using a Weibull model. CONCLUSION: The results of this study highlight that olive leaves extracts can represent a useful ingredient in acidic lipid-containing foods. © 2019 Society of Chemical Industry.

Chemical-nutritional quality and oxidative stability of milk and dairy products obtained from Friesian cows fed with a dietary supplementation of dried grape pomace.

BACKGROUND: The aim of the study was to evaluate the nutritional properties of milk and cheese obtained from Friesian cows fed with a diet supplemented with dried grape pomace, a by-product of the oenological industry, which is very rich in polyphenols. This approach is inspired by the increasing interest in foods containing functional ingredients that may have beneficial effects on human health. During the testing period, analyses of the chemical and nutritional properties of milk and dairy products derived from it were performed; particular attention was given to the effect of cheese ripening on the oxidative stability and fermentation process, evaluating respectively the presence of malondialdehyde and γ-aminobutyric acid. RESULTS: Dietary enrichment with grape pomace did not affect the milk composition but induced modifications in the fatty acid profiles in both milk and cheese with an increase in concentration of linoleic acid, trans-vaccenic acid, rumenic acid and total n-6 fatty acids. Moreover, after 30 days of cheese ripening, an increased oxidative stability and an increased concentration of γ-aminobutyric acid were found. CONCLUSIONS: Our results indicated a general improvement in nutritional parameters of milk and related cheese obtained from Friesian cows that received the feeding enrichment with dried grape pomace. Further analysis should be performed to improve knowledge of the chemical and microbiological mechanisms at the source of these findings. © 2019 Society of Chemical Industry.

Cow milk enriched with nanoencapsulated phenolic extract of jaboticaba (Plinia peruviana).

This study evaluated the total phenolic content (TPC) and the antioxidant activity (AA) of cow's milk enriched with phenolic compounds extracted from jaboticaba peel, either by adding jaboticaba crude extract or a jaboticaba-loaded nanoemulsion. Three nanoemulsions with 5, 10 and 15% of jaboticaba extract were prepared. Average particle diameter (166.7-181.7 nm), polydispersity index (0.138-0.156) and zeta potential (ranging from - 35.30 to - 38.60 mV) were measured for the three different colloidal systems. The nanoemulsion with 15% of jaboticaba extract (J15-NE) was chosen for milk enrichment. J15-NE showed an encapsulation efficiency of 85.6% and remained stable for 60 days at 8 °C. Transmission electron microscopy of J15-NE displayed nanoparticles with a well-defined spherical shape. Reference milk, milk enriched with jaboticaba extract and milk enriched with J15-NE were characterised by a TPC of 93, 171 and 161 µg/ml GAE (gallic acid equivalent), respectively, and an AA of 0.04, 0.17 and 0.14 µg/ml TEAC (trolox equivalent antioxidant capacity), respectively. Thus, this study showed that nanoemulsion with jaboticaba peel extract could be exploited as an ingredient to enrich the properties of milk.

Technological approach to reduce NaCl content of traditional smoked dry-cured hams: effect on quality properties and stability.

The modification of the salting procedure (from a three- to a two-salt coverage steps) and its effects on quality and stability properties has been investigated to reduce NaCl content of traditional dry-cured ham. The study was applied on green hams of small-S and large-L weight classes. Results evidenced that a two-salt coverage steps salting could be applied to reduce significantly NaCl content of S-size hams and to reach the physico-chemical conditions required for microbial stability at the end of ripening. The final salt content of the products results (p < 0.05) to depend on salting procedure and initial weight of the hams, while limited differences on quality properties have been observed being the latter mainly associated to the pattern of the volatile compounds. In particular, aldehydes and hexanal content were lower in hams undergone to a 2-steps salting. Sensory analysis evidenced that the hams with reduced NaCl (2s-S and 2s-L) were less easy to chew, less salty and with a lower intensity of the smoky flavour in respect to the 3s- ones. The study confirmed the feasibility of salt content reduction of traditional dry-cured hams by modifying the salting process. However, the weight of the initial tights resulted a critical factor in affecting salting diffusion, salt content and water activity of the ripened products, their quality and stability properties.

Microencapsulation of hop bioactive compounds by spray drying: Role of inlet temperature and wall material.

This study explores the effect of spray-drying (SD) inlet temperatures (Tinlet 120 and 150 °C) and wall material on the chemical and physico-chemical properties of microencapsulated hop extracts (MHE). Hop extract was formulated with maltodextrin (MD) and gum Arabic (GA) used in single or in combination with ß-cyclodextrin (ßCD). MHE were evaluated for physical properties, bitter acids (BA), total polyphenol content (TPC) and encapsulation efficiency (TPC EE), and antioxidant capacity (AOC). Powders produced at Tinlet 150 °C exhibited the highest flowability and generally higher TPC yield. Besides Tinlet, MD enabled the obtaining of MHE with the highest encapsulation efficiency. Other physico-chemical and antioxidant properties differently varied depending on the Tinlet. Overall, the ßCD addition positively affected α-acids, and ß-acids of MHE obtained at Tinlet 120 °C. ATR-FTIR analysis showed hydrogen bond formation between hop compounds and ßCD. Multifactorial ANOVA highlighted that Tinlet, W, and their interaction influenced almost all the chemical and physico-chemical properties of MHE.

Unraveling the intricate connection between dietary factors and the success in long-term space missions.

In recent decades of spaceflight, inadequate caloric intake has posed significant nutritional challenges, contributing to muscle degradation, weakened immune and cardiovascular systems during and after space missions. This challenge becomes more acute on longer exploration missions, where transporting all food for the entire mission becomes a logistical challenge. This places immense pressure on the food system, requiring energy-dense, varied, stable, and palatable food options. Prolonged storage can lead to nutrient degradation, reducing their bioavailability and bioaccessibility to astronauts. Research is essential not only to improve the quality and stability of space food but also to enhance nutrient bioavailability, thereby reducing weight and volume of food. Muscle and bone loss represent major risks during extended spaceflight, prompting extensive efforts to find exercise countermeasures. However, increased exercise requires additional energy intake, and finding the optimal balance between energy needs and the preservation of muscle and bone mass is challenging. Currently, there is no reliable way to measure total energy expenditure and activity-related energy expenditures in real-time. Systematic research is necessary to develop onboard technology for accurate energy expenditure and body composition monitoring. This research should aim to establish an optimal exercise regimen that balances energy requirements while maintaining astronaut strength and minimizing food transport. In summary, this overview outlines key actions needed for future exploration missions to maintain body mass and physical strength of space travellers. It addresses the requirements for food processing and preservation, considerations for space food formulation and production, and the essential measures to be implemented.

Wild and Micropropagated Artemisia eriantha Infusions: In Vitro Digestion Effects on Phenolic Pattern and Antioxidant Activity.

This study investigated the in vitro simulated gastrointestinal digestion (GID) effects on wild and micropropagated Apennines Genepì infusions. Wild and micropropagated infusions were compared for their antioxidant activity, phenolic contents, and polyphenolic profiles before and after GID. Before digestion, the wild infusions had higher amounts of phenolic compounds and antioxidant activity than the micropropagated ones. Instead, after digestion, the differences in the total phenolic content (TPC) and antioxidant activity between wild and micropropagated infusions were less pronounced. The changes in the TPC and phenolic profiles revealed the presence of several chemical transformations and rearrangements that resulted in compounds with different reactivity and antioxidant potential. Without enzyme actions, the wild infusion digest undergoes higher modifications than those obtained from the micropropagated ones. The current study offers the first concrete proof of the impact of GID on the polyphenolic chemicals present in infusions of wild and micropropagated Apennines Genepì and their antioxidant properties. Our findings are essential for future in-depth analyses of Apennine Genepì infusions and their potential impacts on human health.

Conventional and innovative extraction technologies to produce food-grade hop extracts: Influence on bitter acids content and volatile organic compounds profile.

Hop extracts represent a natural alternative to synthetic food additives because of their high content of bitter acids and volatile organic compounds (VOCs) with bittering, flavoring, and antimicrobial properties. However, broader uses of hop extracts as natural techno-functional ingredients rely on the identification of sustainable and affordable extraction technologies allowing to diversify the processes and produce extracts characterized by different compositions and, consequently, qualitative properties. Thus, this study is aimed to evaluate and compare the effect of innovative and conventional extraction methods on the bitter acids content and VOCs pattern of food-grade ethanolic hop extracts for food applications. Innovative extractions were carried out by using two ultrasound systems (a laboratory bath [US] and a high-power ultrasound bath [HPUS]), and a high-pressure industrial process (high hydrostatic pressure [HHP]). Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60°C; for ultrasound and conventional methods, the effect of the extraction time was also investigated. Among the extracts, the highest and lowest content of bitter acids was found in CONV 60°C extracts, and HHP and CONV 25°C extracts, respectively. Of the 34 VOCs identified in dry hops, ∼24 compounds were found in US, HPUS and CONV extracts, while only 18 were found in HHP. CONV extractions showed higher selectivity for sesquiterpenes, while US and HPUS showed higher selectivity for esters and monoterpenes. Hierarchical cluster analysis (HCA) and partial least squares-discriminant analysis (PLS-DA) allowed classifying hop extracts based on the extraction methods and also allowed highlighting the technological conditions to produce hop extracts with specific techno-functional and flavoring properties. PRACTICAL APPLICATION: The study showed that different extraction methods can lead to hop products with varying sensory and functional properties. By selecting the right extraction method, companies can produce hop extracts with specific compositions that meet their needs for clean label and sustainable food products, as well as new edible packaging or coatings.

Freeze-Drying Microencapsulation of Hop Extract: Effect of Carrier Composition on Physical, Techno-Functional, and Stability Properties.

In this study, freeze-drying microencapsulation was proposed as a technology for the production of powdered hop extracts with high stability intended as additives/ingredients in innovative formulated food products. The effects of different carriers (maltodextrin, Arabic gum, and their mixture in 1:1 w/w ratio) on the physical and techno-functional properties, bitter acids content, yield and polyphenols encapsulation efficiency of the powders were assessed. Additionally, the powders' stability was evaluated for 35 days at different temperatures and compared with that of non-encapsulated extract. Coating materials influenced the moisture content, water activity, colour, flowability, microstructure, and water sorption behaviour of the microencapsulates, but not their solubility. Among the different carriers, maltodextrin showed the lowest polyphenol load yield and bitter acid content after processing but the highest encapsulation efficiency and protection of hop extracts' antioxidant compounds during storage. Irrespective of the encapsulating agent, microencapsulation did not hinder the loss of bitter acids during storage. The results of this study demonstrate the feasibility of freeze-drying encapsulation in the development of functional ingredients, offering new perspectives for hop applications in the food and non-food sectors.

High pressure homogenization to boost the technological functionality of native pea proteins.

Pea proteins are being increasingly used for the formulation of plant-based products, but their globular structure and the presence of aggregates can affect their technological properties. In this study, the effect of high pressure homogenization (HPH) at different intensities (60 and 100 MPa) was investigated as a pre-treatment to modulate the techno-functional properties of a pea protein isolate (IP) extracted through an alkaline extraction/isoelectric precipitation process. SDS-PAGE, circular dichroism, thermal properties, total free sulfhydryl groups, antioxidant capacity and reducing properties were evaluated along with technological indices as solubility, WHC and OHC, interfacial tension and emulsifying capacity. HPH treatments were able to unfold and modify proteins structure, leading also to a change of the relative abundance of pea protein globulins (SDS-PAGE) and of the vicilin to legumin ratio. Solubility, WHC and OHC were improved, while interfacial tension and emulsifying capacity were weakly affected. However, an enhanced physical stability over time of the emulsions prepared with the 60 MPa-treated protein was found, likely as an effect of the decreased ratio between vicilin and legumin after treatment. Results of this study will contribute to deepen the effect of the HPH technology used as pre-treatment, adding useful results and expanding knowledge about the structure and techno-functional properties of native and modified pea proteins.

Degradation kinetics of C-Phycocyanin under isothermal and dynamic thermal treatments.

C-Phycocyanin (C-PC) represents an alternative to artificial blue/green dyes in food products. This study characterized and gained insights into C-PC thermal stability mechanisms and provided a model to estimate its thermal degradation. Aqueous solutions of C-PC (0.3 µM, pH:6.1) were isothermally heated at 45-80 °C. C-PC degradation was monitored based on the photophysical properties of its lumiphores (phycocyanobilins and aromatic aminoacids-AAs). While C-PC was stable at 45 °C, less than 10 min at 80 °C sufficed to degrade most of it. The thermal degradation curves were characterized using the Weibull model, which was validated with data obtained under non-isothermal conditions. Deviations between estimated and experimental values were lower than 8%. Hypsochromic shifts of the AAs' spectra (from 340 to 315 nm) and increase (>30%) in anisotropy at λexc = 280 and 520 nm suggest that colour losses are not solely associated with alterations of the chromophore but also with conformational changes and possible aggregation of the protein subunits.

Starch-based sustainable hydrogel loaded with Crocus sativus petals extract: A new product for wound care.

The aim of the present study was to valorize Crocus sativus petals, the main waste deriving from saffron stigma harvesting, as source of bioactive molecules to be used in health field. Three different dry extracts were prepared by eco-friendly methods (maceration and ultrasound bath assisted maceration) using saffron petals as raw material and ethanol 70 % either ethanol 96 % as extraction solvents. A preliminary evaluation of the antioxidant activity (measured by ABTS*+, DPPH* and FRAP) highlighted that the most suitable extraction solvent is represented by ethanol 70 %. By in vitro studies on keratinocytes emerged that the extract obtained by maceration (rich in gallic and chlorogenic acids) stimulates their growth in a safe concentration range (0.02-0.4 mg/mL) suggesting a potential application in skin diseases such as superficial wounds. Due to the low manageability, the extract was firstly supported on corn starch powder particles and then formulated as starch gel. The obtained formulation showed both suitable rheological properties and spreadability necessary for an easy and pain free application on damaged skin. Moreover, in vitro microbiological studies of starch gel demonstrated antimicrobial activity toward S. epidermidis and self-preserving capacity.

Use of Conventional and Innovative Technologies for the Production of Food Grade Hop Extracts: Focus on Bioactive Compounds and Antioxidant Activity.

This study investigated the use of conventional and innovative extraction methods to produce food-grade hop extracts with high antioxidant capacity and content in bioactive compounds. Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60 °C; innovative extractions were performed using two ultrasound systems, a laboratory bath (US) and a high-power ultrasound bath (HPUS), and a high-pressure industrial process. For CONV, US, and HPUS extractions the effect of the extraction time was also tested. Experimental results showed that extraction method, temperature, and time affect to a different extent the phenolic profile and have a significant effect (p < 0.05) on the total phenolic content, total flavonoid content, antiradical capacity (ABTS), chlorophyll α, and total carotenoids content. Overall, US and CONV 60 °C extractions showed the highest extraction efficiency for almost all the investigated compounds, however, the extraction method and time to be used strongly depends on the target compounds to extract.

Lactic Acid Bacteria Exopolysaccharides Producers: A Sustainable Tool for Functional Foods.

Lactic acid bacteria (LAB) used in the food industry, mainly for the production of dairy products, are able to synthetize exopolysaccharides (EPS). EPS play a central role in the assessment of rheological and sensory characteristics of dairy products since they positively influence texture and organoleptic properties. Besides these, EPS have gained relevant interest for pharmacological and nutraceutical applications due to their biocompatibility, non-toxicity and biodegradability. These bioactive compounds may act as antioxidant, cholesterol-lowering, antimicrobial and prebiotic agents. This review provides an overview of exopolysaccharide-producing LAB, with an insight on the factors affecting EPS production, their dairy industrial applications and health benefits.

Stinging Nettles as Potential Food Additive: Effect of Drying Processes on Quality Characteristics of Leaf Powders.

Stinging nettle (Urtica dioica L.) is a ubiquitous, multi-utility, and under-utilized crop with potential health benefits owing to its nutritional and bioactive components. The objective of the work is to produce powders by drying wild stinging nettle leaves as a storable, low-cost functional additive to be used in bakery and ready-to-cook products. Convective drying (CD) and freeze-drying (FD) were applied on unblanched (U) or blanched (B) leaves, which were then milled to nettle powders (NPs). The obtained NPs were evaluated for selected physicochemical (moisture, color), techno-functional (flow indices, hygroscopicity), and phytochemical (pigments, phenols) characteristics as well as mineral contents. Blanching improved mass transfer and reduced the oxidative degradation of pigments during drying, but it caused a loss of total phenols content, antioxidant activity, and potassium content. As for the drying method, CD resulted in better flow properties (i.e., Carr Index and Hausner Ratio), while FD retained better the color, pigments, magnesium content, phenolic, and antioxidant parameters. Overall, the evaluated processing methods resulted in different technological properties that can allow for better evaluation of NPs as a food additive or ingredient. Among the NPs, blanched and freeze-dried powders despite showing inferior technological properties can be recommended as more suitable ingredients targeted f or food enrichment owing to better retention of bio-active components.

Alginate-based microparticles structured with different biopolymers and enriched with a phenolic-rich olive leaves extract: A physico-chemical characterization.

Encapsulation of olive leaves extracts (OLE), rich of healthy components like Oleuropein, Hydroxytyrosol and Verbascoside, represents a new challenge to improve stability and nutritional value of food as well as a way to recover value added compounds from by-products, contributing to a more sustainable food system. In this context, OLE-loaded microbeads of Na alginate alone or in combination with Pectin, Na Caseinate or Whey protein isolates, were produced by emulsification internal ionotropic gelation. Encapsulation efficiency of the main phenolic compounds (Oleuropein, Hydroxytyrosol, Verbascoside) was carried out along with microparticles morphological characterization by scanning electron microscopy (SEM), thermal properties by differential scanning calorimetry (DSC) and color. Encapsulation efficiency resulted higher for Alginate/Pectin, whilst Alginate/Caseinate was the less performing system, probably due to the lower interaction with polyphenols. SEM revealed collapsed structures and continuous smooth surfaces for Alginate and Alginate/Pectin microbeads while more regular structures and porous surfaces were observed for Alginate/Caseinate and Alginate/Whey proteins. Higher hue angle and lower chroma values were observed for all the beads with respect to the pure extract, indicating a reduction of the yellow/brown color. DSC highlighted higher thermal stability for the microbeads in comparison to the original ingredients, showing also new thermal transitions related to bonds formation between polymers and OLE.