Apple Pomace Extract as a Sustainable Food Ingredient

A New Approach to Recover Bioactive Compounds from Apple Pomace: Healthy Jelly Candies

Rich in bioactive compounds, carbohydrates, fibers, minerals, and trace elements, apple pomace (AP) is a significant agro-industrial by-product, which pollutes and brings high management costs. The current study investigates the possibility of using an aqueous AP extract (APE) as the main ingredient in a jelly candy recipe, replacing artificial colors and flavors and improving its nutritional value. APE and formulated jelly candies were analyzed in terms of their phytochemical profile, antioxidant capacity, and color parameters. In addition, the microbiological and sensory properties of the jelly candies, as well as their behavior during storage, were analyzed. An HPLC analysis of AP revealed the presence of 9 individual phenolic compounds, with a high content of protocatechuic (375.21 ± 18.76 µg/g DW) and p-hydroxybenzoic (164.96 ± 13.83 µg/g DW) acids. The results of this study prove the presence of bioactive compounds with antioxidant and antidiabetic properties in both APE and its candies. Investigation on jelly candies with APE revealed an antioxidant capacity of 142.03 ± 1.08 mmol TE/g DW and a total polyphenolic content of 8.25 ± 0.17 mg GAE/g DW. Additionally, a sensory analysis highly appreciated the proposed jelly with APE, with scores higher than 4.70/5.00 for all evaluated attributes. Thus, this study succeeded in developing a new approach to recovering bioactive compounds from AP, demonstrating the potential of this by-product to improve jelly candies' attributes while promoting sustainability through waste reduction and the effective use of natural resources.

Cocoa shell ingredients improve their lipid-lowering properties under simulated digestion: In vitro and HepG2 cells study

Cocoa (Theobroma cacao) shell, the main by-product of cocoa industry, is associated with the regulation of several biomarkers of metabolic syndrome. However, there is little information about the digestion effect on the physiological properties of cocoa shell. The aim of this study was to assess the impact of a standardized in vitro digestion protocol on the hypolipidemic capacity of two cocoa shell ingredients, a flour (CSF) and an aqueous extract (CSE), through the evaluation of their in vitro hypolipidemic properties and lipid-lowering effects in HepG2 cells. CSF and CSE digested fractions increased their capacity to bind primary bile acids (16-88 %) and inhibit lipase activity (41-100 %), while their ability to bind secondary bile acids (33-42 %) was maintained. Likewise, the digested fractions of cocoa shell ingredients reduced the solubility of the cholesterol micelles (35-97 %) and inhibited the hydroxymethylglutaryl-Co-enzyme A reductase (HMGCR) activity (18-100 %). The hypolipidemic properties of non-digested fractions further enhanced the CSF potential to decrease lipid absorption. Cocoa shell ingredients demonstrated lipid-lowering properties after simulated digestion by effectively reducing the accumulation of intracellular lipids (78-122 %), triacylglycerides (60-90 %), and cholesterol (100 %) induced by palmitic acid in hepatic cells. These results were confirmed by their ability to stimulate lipolysis, reducing the increase in lipase activity (28-78 %) and increasing glycerol release (27-80 %) with respect to palmitic acid treated cells, and inhibiting HMGCR activity. Phenolic compounds and dietary fiber are significantly associated to the observed hypolipidemic effects of cocoa shell ingredients. These findings demonstrated the potential efficacy of CSF and CSE in reducing lipid absorption and reversing its hepatic accumulation. Hence, these cocoa shell ingredients might prevent diseases related to lipid accumulation by improving overall health status.

Chemodiversity of Arctic Plant Dryas oxyodonta: LC-MS Profile and Antioxidant Activity

Dryas oxyodonta Yuz. is a perennial evergreen shrub from the Rosaceae family. D. oxyodonta thrives in subalpine and subarctic regions, as well as in highlands spanning from Central Asia to Siberia and Mongolia. Owing to a lack of information on its chemical composition, we conducted qualitative and quantitative chromatographic analyses on extracts from the leaves and flowers of D. oxyodonta sourced from various Siberian habitats. Employing high-performance liquid chromatography with photodiode-array detection and electrospray ionization triple-quadrupole mass spectrometric detection, we identified 40 compounds, encompassing gallotannins, hydroxycinnamates, procyanidins, catechins, flavonoids, and triterpenes. All Siberian populations of D. oxyodonta exhibited a notable abundance of phenolic compounds. Furthermore, we identified rare glycosides, such as sexangularetin and corniculatusin, as potential markers of the chemodiversity within the Dryas genus. Extracts from the flowers and leaves were effective scavengers of free radicals, including DPPH•, ABTS•+-, O2•-, and •OH radicals. Our findings unequivocally establish D. oxyodonta as a rich source of phenolic compounds with potent antioxidant activity, suggesting its potential utility in developing novel functional products.

Sustainable utilization of apple pomace and its emerging potential for development of functional foods

Apple pomace, a byproduct of apple processing industry, possesses nutritional components which are of great interests for health aspects. Apple pomace is a good source of dietary fiber, minerals, carbohydrates, phenolic, and antioxidant compounds. These bioactive compounds can be extracted by different extraction techniques which have been comprehensively described in this review article. Furthermore, the incorporation of apple pomace as functional ingredients in different food products like bakery items, extrusion-based snacks, meat, dairy, and confectionary products to improve the commercial value and health benefits has been discussed briefly. This review article can be a helpful tool for industrialists, innovative researchers, and waste management authorities to manage the apple waste in an appropriate and sustainable way.

The Use of Fruit and Vegetable by-Products as Enhancers of Health Status of Piglets after Weaning: The Role of Bioactive Compounds from Apple and Carrot Industrial Wastes

At weaning, piglets are exposed to a large variety of stressors, from environmental/behavioral factors to nutritional stress. Weaning transition affects the gastrointestinal tract especially, resulting in specific disturbances at the level of intestinal morphology, barrier function and integrity, mucosal immunity and gut microbiota. All these alterations are associated with intestinal inflammation, oxidative stress and perturbation of intracellular signaling pathways. The nutritional management of the weaning period aims to achieve the reinforcement of intestinal integrity and functioning to positively modulate the intestinal immunity and that of the gut microbiota and to enhance the health status of piglets. That is why the current research is focused on the raw materials rich in phytochemicals which could positively modulate animal health. The composition analysis of fruit, vegetable and their by-products showed that identified phytochemicals could act as bioactive compounds, which can be used as modulators of weaning-induced disturbances in piglets. This review describes nutritional studies which investigated the effects of bioactive compounds derived from fruit (apple) and vegetables (carrot) or their by-products on the intestinal architecture and function, inflammatory processes and oxidative stress at the intestinal level. Data on the associated signaling pathways and on the microbiota modulation by bioactive compounds from these by-products are also presented.

Fruit waste: a current perspective for the sustainable production of pharmacological, nutraceutical, and bioactive resources

Fruits are crucial components of a balanced diet and a good source of natural antioxidants, that have proven efficacy in various chronic illnesses. Various kinds of waste generated from fruit industries are considered a global concern. By utilizing this fruit waste, the international goal of "zero waste" can be achieved by sustainable utilization of these waste materials as a rich source of secondary metabolites. Moreover, to overcome this waste burden, research have focused on recovering the bioactive compounds from fruit industries and obtaining a new strategy to combat certain chronic diseases. The separation of high-value substances from fruit waste, including phytochemicals, dietary fibers, and polysaccharides which can then be used as functional ingredients for long-term health benefits. Several novel extraction technologies like ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE) could provide an alternative approach for successful extraction of the valuable bioactives from the fruit waste for their utilization as nutraceuticals, therapeutics, and value-added products. Most of these waste-derived secondary metabolites comprise polyphenols, which have been reported to have anti-inflammatory, insulin resistance-treating, cardiovascular disease-maintaining, probiotics-enhancing, or even anti-microbial and anti-viral capabilities. This review summarizes the current knowledge of fruit waste by-products in pharmacological, biological, and probiotic applications and highlights several methods for identifying efficacious bioactive compounds from fruit wastes.

Polyphenol Profiling by LC QTOF/ESI-MS and Biological Activity of Purple Passion Fruit Epicarp Extract

A polyphenolic preparation in the form of the passion fruit epicarp extract was analyzed to identify and quantify the polyphenolic compounds using LC QTOF/ESI-MS and UPLC-PDA-FL. The analyzed parameters included antidiabetic activity (α-amylase, α-glucosidase, and pancreatic lipase), inhibitory activity toward cholinesterase (AChE, BuChE), anti-inflammatory activity (COX-1, COX-2, 15-LOX) and antioxidant activity based on ORAC and ABTS. The polyphenolic preparation of the passion fruit epicarp extract contained 51 polyphenolic compounds representing five groups-flavones (25 compounds; 52% of total polyphenolic), flavonols (8; 16%), flavan-3-ols (6; 7%), phenolic acids (4; 3%), and anthocyanins (7; 21%), with derivatives of luteolin (13 derivatives) and apigenin (8 derivatives) as dominant compounds. The preparation was characterized by an antioxidant activity of 160.7 (ORAC) and 1004.4 mmol Trolox/100 mL (ABTS+o). The inhibitory activity toward α-amylase, α-glucosidase, and pancreatic lipase reached IC50 of 7.99, 12.80, and 0.42, respectively. The inhibition of cholinesterases (IC50) was 18.29 for AChE and 14.22 for BuChE. Anti-inflammatory activity as IC50 was 6.0 for COX-1, 0.9 for COX-2, and 4.9 for 15-LOX. Food enriched with passion fruit epicarp extract has a potentially therapeutic effect.

Evolution of physico-chemical parameters, microorganism diversity and volatile organic compound of apple pomace exposed to ambient conditions

In apple processing, waste material known as apple pomace amounts to 45% of production volumes. When this residue is stored in open-air for its stabilization and potential uses, Volatile Organic Compounds (VOCs) are produced, resulting in environmental and odor pollution, and must be managed to avoid their impact. This work aims to study the emission of VOCs utilizing TD-GC/MS and its relationship with changes in physico-chemical (moisture, pH, proteins, among others) and biological (bacteria and fungi using Illumina MiSeq) parameters under three environmental conditions: open-air (outdoors), under-roof (indoors) and oxygen-free. The 8-month study results showed a gradual increase in odorous VOCs and microbial diversity, a product of chemical and biological transformation processes in the samples. A 30% increase in odorant compounds responsible for the unpleasant smell was observed, especially esters, aldehydes and hydrocarbons in samples stored in oxygen-free and Open-air conditions. Increases in VOCs over time were associated with changes in physico-chemical and biological parameters, as well as fluctuations in environmental variables (temperature, relative humidity, and precipitation). The results of this research allow establishing a relationship between storage conditions and the production of VOCs. In addition, recommendations for waste storage time are provided for the most common uses of apple pomace based on the physico-chemical parameters observed, in order to avoid the generation of odorous compounds. Of all storage methods analyzed, under-roof is the most adequate in practice. This study's findings are pertinent for managing agribusiness waste and its potential environmental pollution.

The antioxidant activity of polysaccharides: A structure-function relationship overview

Over the last years, polysaccharides have been linked to antioxidant effects using both in vitro chemical and biological models. The reported structures, claimed to act as antioxidants, comprise chitosan, pectic polysaccharides, glucans, mannoproteins, alginates, fucoidans, and many others of all type of biological sources. The structural features linked to the antioxidant action include the polysaccharide charge, molecular weight, and the occurrence of non-carbohydrate substituents. The establishment of structure/function relationships can be, however, biased by secondary phenomena that tailor polysaccharides behavior in antioxidant systems. In this sense, this review confronts some basic concepts of polysaccharides chemistry with the current claim of carbohydrates as antioxidants. It critically discusses how the fine structure and properties of polysaccharides can define polysaccharides as antioxidants. Polysaccharides antioxidant action is highly dependent on their solubility, sugar ring structure, molecular weight, occurrence of positive or negatively charged groups, protein moieties and covalently linked phenolic compounds. However, the occurrence of phenolic compounds and protein as contaminants leads to misleading results in methodologies often used for screening and characterization purposes, as well as in vivo models. Despite falling in the concept of antioxidants, the role of polysaccharides must be well defined according with the matrices where they are involved.

Apples and Apple By-Products: Antioxidant Properties and Food Applications

In recent years, there has been a growing interest in utilizing natural antioxidants as alternatives to synthetic additives in food products. Apples and apple by-products have gained attention as a potential source of natural antioxidants due to their rich phenolic content. However, the extraction techniques applied for the recovery of phenolic compounds need to be chosen carefully. Studies show that ultrasound-assisted extraction is the most promising technique. High yields of phenolic compounds with antioxidant properties have been obtained by applying ultrasound on both apples and their by-products. Promising results have also been reported for green technologies such as supercritical fluid extraction, especially when a co-solvent is used. Once extracted, recent studies also indicate the feasibility of using these compounds in food products and packaging materials. The present review aims to provide a comprehensive overview of the antioxidant properties of apples and apple by-products, their extraction techniques, and potential applications in food products because of their antioxidant or nutritional properties. The findings reported here highlight the proper utilization of apples and their by-products in food to reduce the detrimental effect on the environment and provide a positive impact on the economy.

Physicochemical Characteristics, Antioxidant Properties and Consumer Acceptance of Greek Yogurt Fortified with Apple Pomace Syrup

Despite having high polyphenolic phytochemicals and functional components, apple pomace (AP) is often discarded in landfills, leading to pollution. The study aimed to find a sustainable application for AP in Greek yogurt fortified with AP syrup (APS). Physicochemical characteristics and antioxidant properties were analyzed for APS (APS0.00, APS1.25, APS2.50, APS3.75, APS5.00). As the AP content in the syrup increased, moisture content, titratable acidity, and viscosity significantly increased (p < 0.05). The total polyphenols and flavonoid content of APS increased with increasing AP content. In Greek yogurt fortified with APS (APY), reducing sugar content (0.55 mg/mL to 0.71 mg/mL) significantly increased with fermentation time and AP content, whereas pH level (6.85 to 4.28) decreased. The antioxidant activities by DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power, and reducing power were also significantly increased with the AP content and fermentation time. In the consumer acceptance test of APY, APY1.25 had significantly high scores in overall acceptance, taste acceptance, and aftertaste acceptance with purchase intent (p < 0.05). The Greek yogurt fortified with APS as functional food had improved antioxidant properties and consumer acceptance, suggesting the possibility of developing sustainable AP products.

Performance and meat quality of broiler chickens fed with the addition of dried fruit pomace

The aim of the study was to evaluate the addition to feed of 3% of dried pomace from apples (AP), cherries (CH), and strawberries (ST) on the production results and meat quality of broiler chickens. Birds fed only the standard mixture for broiler chickens were the control group (CO). On d 42, a lower body weight of broiler chickens from group ST was noted compared to birds from group CO at P = 0.032. When feed conversion per 1 kg of weight gain and loss of broiler chickens was assessed, no differences between groups were shown (P ˃ 0.05). The leg muscles of AP and CH broiler chickens had less drip loss compared to the control group at P = 0.036. For other quality parameters of breast and leg muscles, no differences between groups were noted (P ˃ 0.05). It was found that the addition of dried apple and cherry pomace to the feed in the amount of 3% did not adversely affect the production results and the quality of broiler chicken meat. On the other hand, the addition to feed of dried pomace from strawberries reduced the final body weight of experimental birds. The most interesting additive turned out to be dried cherry pomace, because it improved slaughter efficiency, contributed to reducing drip loss of leg muscles, and influenced the lower level of crude fat in the breast muscles. However, further research should be carried out on the optimal concentration of CH in the diet of fattening chickens in order to achieve the most beneficial results.

Multivariate analysis of structural and functional properties of fibres from apple pomace using different extraction methods

In recent years, diets rich in fibres have become more popular due to their well-documented beneficial health effects. This has driven exploration of novel dietary fibres from various bioresources. Apple pomace, an industrial waste rich in fibres was used in this study to extract the insoluble dietary fibres. The effect of various extraction methods (hot water, acid, and alkali) on the physico-chemical, structural and functional properties, and prebiotic activity of dietary fibres was evaluated. Hot water extraction resulted in highest yield of dietary fibres in comparison to other methods (p < 0.05). All the fractions resulted in different organization of fibrous components as depicted by scanning electron micrographs, Fourier Transform Infrared spectroscopy (FTIR), X-Ray Diffraction (XRD) pattern and Thermo Gravimetric Analysis (TGA). The acid extracted fibre fraction was observed to be amorphous with loose and porous structure whereas the alkali extracted fraction was more thermal stable based on TGA profile. Among the functional properties, acid extracted dietary fibres fraction possessed highest water and oil holding capacity (p < 0.05). The hot water extracted dietary fraction resulted in maximum increase in viable cell count of standard probiotic strains Lactobacillus sporogenes and Streptococcus faecalis. The Principal Component Analysis revealed that acid extracted fraction possessed better functional activity which also correlates with the structural properties whereas for prebiotic activities, the fibre obtained from hot water extraction method served the best method. These results indicate that dietary fibres extracted through hot water can be employed as a potential prebiotic substrate for the probiotic cultures and could be further explored in foods to improve textural, functional, and bioactive properties of foods.

Graphical Abstract

Locust bean milling-derived dust as a raw material for the development of biodegradable bioplastics with antioxidant activity

BACKGROUND

Non-value agrifood byproducts are rich in biomolecules such as proteins and polysaccharides, and possess film-forming ability, motivating their use in the development of biodegradable plastics. This work studied the feasibility of using locust bean milling-derived dust (LBMD) as a source of biomolecules suitable for developing biodegradable plastics.

RESULTS

LBMD is composed of 56% protein, 28% carbohydrate, 10% moisture, 6% lipid, and 2% ash. In addition, phenolic compounds are also present. The carbohydrates are mainly composed by (1 → 4)-mannose, (1 → 4,6)-mannose, and t-galactose glycosidic linkages. Depending on the LBMD concentration used, when employed in casting biodegradable plastics, LBMD yields transparent yellowish bioplastics with 90% elongation at break and surface water contact angles ranging from 60° to 90°. Additionally, LBMD-based bioplastics display antioxidant activity, inhibiting cationic 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals up to 61% in just 24 h. LBMD-based bioplastics are disintegrated when incubated on the soil surface for 34 weeks, perhaps acting as a soil nutrient.

CONCLUSION

LBMD represents a potential source of biomolecules for producing transparent, flexible, water tolerant, antioxidant, and biodegradable bioplastics, opening up opportunities to implement a novel circular strategy to valorize this locust bean industry byproduct. © 2022 Society of Chemical Industry.

Phytochemicals Derived from Agricultural Residues and Their Valuable Properties and Applications

Billions of tons of agro-industrial residues are produced worldwide. This is associated with the risk of pollution as well as management and economic problems. Simultaneously, non-edible portions of many crops are rich in bioactive compounds with valuable properties. For this reason, developing various methods for utilizing agro-industrial residues as a source of high-value by-products is very important. The main objective of the paper is a review of the newest studies on biologically active compounds included in non-edible parts of crops with the highest amount of waste generated annually in the world. The review also provides the newest data on the chemical and biological properties, as well as the potential application of phytochemicals from such waste. The review shows that, in 2020, there were above 6 billion tonnes of residues only from the most popular crops. The greatest amount is generated during sugar, oil, and flour production. All described residues contain valuable phytochemicals that exhibit antioxidant, antimicrobial and very often anti-cancer activity. Many studies show interesting applications, mainly in pharmaceuticals and food production, but also in agriculture and wastewater remediation, as well as metal and steel industries.

Empire Apple (Malus domestica) Juice, Pomace, and Pulp Modulate Intestinal Functionality, Morphology, and Bacterial Populations In Vivo (Gallus gallus)

Approximately $20 billion of apple sales are generated annually in the United States. With an estimated 5 million tons produced yearly in the U.S. within the last decade, apple consumption is considered ubiquitous. Apples are comprised of bioactive constituents such as phytochemicals and prebiotics that may potentiate intestinal health and the gut microbiome. This study aimed to evaluate the effects of Empire apple juice, pomace, and pulp soluble extracts on intestinal functionality, morphology, and the microbiome in vivo (Gallus gallus). There were five treatment groups: non-injected (NI); 18 MΩ H2O (H2O); 6% apple juice (AJ); 6% apple pomace (APo); 6% apple pulp (APu). The eggs were treated by intra-amniotic administration of the samples on day 17 of incubation. After hatching, the blood, tissue, and cecum samples were collected for further analyses—including duodenal histomorphology, hepatic and duodenal mRNA expression, and cecal bacterial populations. Crypt depth was significantly (p < 0.5) shortest in AJ when compared to APo and APu. APo and APu soluble extracts significantly improved villi surface area compared to NI and H2O control groups. The highest count of Paneth cells per crypt was observed in APo as compared to all groups. In addition, the expression of brush border membrane micronutrient metabolism and functional proteins varied between treatments. Lastly, Lactobacillus cecal microbial populations increased significantly in the AJ group, while AJ, APu, and APu increased the abundance of Clostridium (p < 0.5). Ultimately, these results indicate the potential of Empire apple pomace to improve host intestinal health and the gut microbiome.

Polyphenols from Thinned Young Apples: HPLC-HRMS Profile and Evaluation of Their Anti-Oxidant and Anti-Inflammatory Activities by Proteomic Studies

The qualitative profile of thinned apple polyphenols (TAP) fraction (≈24% of polyphenols) obtained by purification through absorbent resin was fully investigated by LC-HRMS in positive and negative ion mode and using ESI source. A total of 68 polyphenols were identified belonging to six different classes: flavanols, flavonols, dihydrochalchones, flavanones, flavones and organic and phenolic acids. The antioxidant and anti-inflammatory activities were then investigated in cell models with gene reporter for NRF2 and NF-κB and by quantitative proteomic (label-free and SILAC) approaches. TAP dose-dependently activated NRF2 and in the same concentration range (10–250 µg/mL) inhibited NF-κB nuclear translocation induced by TNF-α and IL-1α as pro-inflammatory promoters. Proteomic studies elucidated the molecular pathways evoked by TAP treatment: activation of the NRF2 signaling pathway, which in turn up-regulates protective oxidoreductases and their nucleophilic substrates such as GSH and NADPH, the latter resulting from the up-regulation of the pentose phosphate pathway. The increase in the enzymatic antioxidant cellular activity together with the up-regulation of the heme-oxygenase would explain the anti-inflammatory effect of TAP. The results suggest that thinned apples can be considered as a valuable source of apple polyphenols to be used in health care products to prevent/treat oxidative and inflammatory chronic conditions.

A review on membrane separation processes focusing on food industry environment-friendly processes

Food processing industries have led to several environmental impacts due to their high water and energy consumption, as well as soil and water bodies' contamination through improper waste disposal. Membrane Separation Processes (MSP) emerge as an important alternative to enable the adoption of sustainable processes by food industries, since satisfying the requests of innovative processes and equipment design, such as smaller, cleaner, more energy-efficient processes (mild conditions) without the usage of chemical agents. Membrane-based processes fulfill these requirements, and their potential has been broadly recognized in the last few years. This review provides a comprehensive and up-to-date overview of the application of MSP in sustainable processes in the different segments of the food industry over the last 10 years. Waste and wastewater treatment, recovery of valuable compounds and water for reuse, and alternatives to high energy consumption processes were identified as sustainable processes in this context. One trend found is the potential for adding value to production chains by obtaining valuable compounds that have not been explored yet. As a perspective for future research, this review showed that it is advisable to implement MSP in different industrial environments in order to make current processes environmentally sustainable and less polluting.

Methane Production Potential from Apple Pomace, Cabbage Leaves, Pumpkin Residue and Walnut Husks

Circular economy aims to eliminate organic waste through its transformation, composting and processing into other products or energy. The main aim of the study was to determine the specific methane yield (SMY) of anaerobic digestion (AD) of four different fruit and vegetable residues (FVR). In addition, the reduction in greenhouse gas (GHG) emissions was calculated based on the assumption that maize will be replaced by the FVR as a feedstock for biogas production. The SMY of four residues (apple pomace, cabbage leaves, pumpkin peels and fibrous strands and walnut husks) was measured in the biomethane potential test (BMP) in wet anaerobic digestion technology. The highest SMY (297.81 ± 0.65 NL kgVS−1) was observed for cabbage leaves while the lowest SMY (131.07 ± 1.30 kgVS−1) was found for walnut husks. The concentrations of two inhibitory gasses (NH3 and H2S) in biogas were low and did not affect the AD process. Only biogas produced from cabbage leaves was characterised by higher NH3 and H2S concentrations resulting from the highest protein concentration in this waste. FVR used as feedstock in biogas production may decrease the area of maize cultivation. Therefore, the GHG emissions from maize cultivation will be reduced. In Poland only, the use of four studied FVR as feedstock for biogas production would contribute to the reduction of GHG emissions by 43,682 t CO2 eq.

Performance of Apple Pomace for Gluten-Free Bread Manufacture: Effect on Physicochemical Characteristics and Nutritional Value

Apple pomace has been proposed as a quality enhancer for gluten-free bread, but its composition and physicochemical features differ significantly depending on the apple cultivar. The objective of this article was to characterize apple pomace powder (APP) from certain varieties from the Basque Country and to study the feasibility of adding it to gluten-free bread, focusing on physicochemical and nutritional aspects. APP was obtained by washing, drying and grinding, and it was added at 0, 5, 6 and 8%, together with other ingredients, such as gluten-free flours, corn starch and whey protein. APP had a reddish-grey coloration (L* 56.49 ± 1.39, a* 11.07 ± 0.47, b* 27.69 ± 1.76), pH 4.19 ± 0.15 and Aw 0.235 ± 0.084. Pomace powder was used successfully in higher amounts than experiences reported before. Key physicochemical parameters such as specific volume (≥2.5 cm3/g) and cohesiveness or resilience values (0.538 and 0.378, respectively) suggested good acceptability for gluten-free breads with 8% APP. Additionally, breads were a source of antioxidant potential (437.66 ± 38.95 µM DPPHeq/g APP), fiber (80.13 ± 6.07 g/100 g) and micronutrients such as Cu, Mg, Mn and Fe. In conclusion, local apple varieties are a good source of raw material for gluten-free bread manufacture, which offers a solution for environmental pollution and may contribute to boosting the circular economy.

Analysis of Fatty Acids, Amino Acids and Volatile Profile of Apple By-Products by Gas Chromatography-Mass Spectrometry

Apple industrial by-products are a promising source of bioactive compounds with direct implications on human health. The main goal of the present work was to characterize the Jonathan and Golden Delicious by-products from their fatty acid, amino acid, and volatile aroma compounds’ point of view. GC-MS (gas chromatography-mass spectrometry) and ITEX/GC-MS methods were used for the by-products characterization. Linoleic and oleic were the main fatty acids identified in all samples, while palmitic and stearic acid were the representant of saturated ones. With respect to amino acids, from the essential group, isoleucine was the majority compound identified in JS (Jonathan skin) and GS (Golden skin) samples, lysine was the representant of JP (Jonathan pomace), and valine was mainly identified in GP (Golden pomace). A total number of 47 aroma volatile compounds were quantified in all samples, from which the esters groups ranged from 41.55–53.29%, aldehydes 29.75–43.99%, alcohols from 4.15 to 6.37%, ketones 4.14–5.72%, and the terpenes and terpenoids group reached values between 2.27% and 4.61%. Moreover, the by-products were valorized in biscuits manufacturing, highlighting their importance in enhancing the volatile aroma compounds, color, and sensorial analysis of the final baked goods.

Effect of Freeze-Drying on Apple Pomace and Pomegranate Peel Powders Used as a Source of Bioactive Ingredients for the Development of Functional Yogurt

Agro-industrial by-products of fruits have turned into an essential source of bioactive products. This study examined the effect of freeze-drying on apple pomace powder (APP) and pomegranate peel powder (PPP) and their utilization in functional yogurt development at different concentrations. Freeze-dried powders in functional yogurt were investigated by chemical profile and bioactive characterization of total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. The highest concentration of TPC (4.64) mg GAE/g, TFC (1.73 ± 0.00) CE mg/g, and antioxidant activity (83.87 ± 0.02) % was investigated in the yogurt sample T6, having the maximum amount of PPP in it, which was significantly higher compared to the treatments having APP. Yogurt samples were analyzed for their sensory attributes, which showed a decline with the increase in both APP and PPP concentrations in contrast by introducing the optimum levels of APP and PPP (3% or 6%); hence, no significant loss in sensory profile was found as compared to the control samples. The results were found to be significant at the level ( $p<0.05$ ). In terms of the freeze-dried APP and PPP results, the APP samples had the most complete chemical composition, with the exception of fiber and ash concentration. Treatments of functional yogurt were prepared for their physicochemical profile, which demonstrated a straight proportionate relationship between the proportions of both powders in the meantime. Protein and fat levels were likely to decrease as both dry powder levels increased. Hence, apple pomace and pomegranate peel can be used after freeze-drying as a rich source of bioactive compounds in functional yogurt in the food industry.

Influence of the extraction method on the recovery of bioactive phenolic compounds from food industry by-products

Agro-foodindustries generate colossal amounts of non-edible waste and by-products, easily accessible as raw materials for up-cycling active phytochemicals. Phenolic compounds are particularly relevant in this field given their abundance in plant residues and the market interest of their functionalities (e.g. natural antioxidant activity) as part of nutraceutical, cosmetological and biomedical formulations. In "bench-to-bedside" achievements, sample extraction is essential because valorization benefits from matrix desorption and solubilization of targeted phytocompounds. Specifically, the composition and polarity of the extractant, the optimal sample particle size and sample:solvent ratio, as well as pH, pressure and temperature are strategic for the release and stability of mobilized species. On the other hand, current green chemistry environmental rules require extraction approaches that eliminate polluting consumables and reduce energy needs. Thus, the following pages provide an update on advanced technologies for the sustainable and efficient recovery of phenolics from plant matrices.

Microwave hydrodiffusion and gravity as a sustainable alternative approach for an efficient apple pomace drying

Apple pomace valuation has been impaired by its high perishability and absence of fast drying approaches demanded by industry. This work aimed to assess the feasibility of Microwave Hydrodiffusion and Gravity (MHG) process applied for apple pomace drying using discrete delivery powers (300-900 W) and comparison with hot-air drying (40-100 °C). To dry 0.4 kg of apple pomace (81% moisture), hot-air drying required 3.6-9.9 h with estimated water evaporation flux of 1.0-3.5 mL/min. For MHG, which processed 1.2 kg, these corresponded to 1.0-2.6 h and 5.1-13.9 mL/min. Furthermore, MHG allowed water recovery containing part of apple pomace phenolic compounds and carbohydrates. The dried pomace was stable for 2 years, after which phenolic compounds and polysaccharides were still recoverable by hot water extractions. These results pave the way for MHG to be used for apple pomace and other by-products preservation, boosting their conversion into valuable co-product for valuation of its components.

The Perspective of Croatian Old Apple Cultivars in Extensive Farming for the Production of Functional Foods

The Republic of Croatia has a long tradition of fruit growing due to its geographical location, climatic conditions, and high quality of fruit crops, especially apple fruits. Apples can be used for the formulation of functional foods either in processed form (e.g., juice), or as a by-product (e.g., apple pomace). However, there is a growing demand for functional foods derived from ancient and traditional plant sources as they are recognized as a very valuable source of health-promoting bioactive ingredients. Similarly, old apple cultivars (Malus domestica Borkh.) are characterized by good morphological and pomological properties, less need for chemicals during cultivation and the higher share of biologically active compounds (BACs) with better sensory acceptability compared to commercial cultivars. However, their nutritional and biological potential is underestimated, as is their ability to be processed into functional food. The importance in preserving old apple cultivars can also be seen in their significance for improving the nutritional composition of other apple cultivars through innovative cultivation strategies, and therefore old local apple cultivars could be of great importance in future breeding programs.

Concentrate Apple Juice Industry: Aroma and Pomace Valuation as Food Ingredients

Apple concentrate juice industry generates a flavored coproduct (apple aroma) recovered in the evaporation process, which is poorly valuated due to the lack of chemical characterization and standardization. In this study, industry apple aroma was characterized, allowing for the identification of 37 compounds, the majority esters (20), alcohols (7), and aldehydes (4). The storage temperature did not affect its volatile composition. Five key compounds were selected and monitored for 10 months of storage, and also compared with other three productions of another season allowing for observation of the same Aroma Index. Apple pomace was also used to produce a hydrodistillate. Contrary to the apple aroma, apple pomace hydrodistillate was unpleasant, reflected in a different volatile composition. Although no additional aroma fraction could be obtained from this wet byproduct, when dried, apple pomace presented 15 volatile compounds with toasted, caramel, sweet, and green notes. The infusions prepared with the dried apple pomace exhibited 25 volatile compounds with a very pleasant (fruity, apple-like, citrus, and spicy notes) and intense aroma. The addition of sugar changed the volatile profile, providing a less intense flavor, with almond, caramel, and sweet notes. These results show that apple aroma and pomace are high-quality flavoring agents with high potential of valuation as food ingredients.

Evaluation of Metabolite Profiles of Ginseng Berry Pomace Obtained after Different Pressure Treatments and Their Correlation with the Antioxidant Activity

Ginseng berry pomace (GBP) is a byproduct of ginseng berry processing and is rich in numerous bioactive components, including ginsenosides and their derivatives. The application of GBP as a beneficial biomaterial is currently limited. In this study, we aimed to evaluate their potential as a promising source of bioactive compounds using metabolite profiling. The GBP obtained after different ultra-high-pressure (UHP) treatments was analyzed by GC-TOF-MS and UHPLC-LTQ-Orbitrap-MS/MS. In multivariate analyses, we observed a clear demarcation between the control and UHP-treated groups. The results demonstrated that the relative abundance of primary metabolites and a few ginsenosides was higher in the control, whereas UHP treatment contained higher levels of fatty acids and sugars. Furthermore, GBPs were fractionated using different solvents, followed by UHPLC-LTQ-Orbitrap-MS/MS analyses. The heatmap revealed that phenolics (e.g., quercetin, kaempferol) and fewer polar ginsenosides (e.g., F4, Rh2) were abundant in the ethyl acetate fraction, whereas the levels of lignans (e.g., 7-hydroxysecoisolariciresinol, syringaresinol) and fatty acids (e.g., trihydroxy-octadecenoic acid, oxo-dihydroxy-octadecenoic acid) were high in chloroform. Correlation analysis showed that phenolics, less polar ginsenosides, and fatty acids were positively correlated with the antioxidant activity of GBP. Our study highlights GBP as a functional ingredient for the development of high-quality ginseng berry products.

Development of red apple pomace extract/chitosan-based films reinforced by TiO2 nanoparticles as a multifunctional packaging material

A chitosan-based (CS) film was developed with nanosized TiO₂ and red apple pomace extract (APE). The intermolecular interactions of CS, TiO₂ and APE were evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. TiO₂ nanoparticles remarkably improved the water vapor and UV-Vis light barrier properties, mechanical strength and thermal stability of CS-APE films. The strong antioxidant abilities of CS-APE and CS-TiO₂-APE films were characterized. Nano-TiO₂ and APE showed a synergistic enhancement of the antimicrobial activity in CS matrix. The addition of TiO₂ nano-particles into CS-APE films resulted the sensitive color variations, which applied successfully as an indicator to monitor the freshness of salmon fillets. Consequently, the development of CS-APE-TiO₂ film provides a new solution to convert rad apple pomace to an active and multifunctional food packaging material with considerable mechanical, antibacterial, antioxidant and pH-responsive color-changing properties.

Sensory and Conceptual Aspects of Ingredients of Sustainable Sources-Finnish Consumers' Opinion

Sustainable strategies that enable development of alternative sustainable novel ingredients for food are needed to ensure adequate resources for food in the future. Determining consumer attitudes and acceptance of novel ingredients is essential for wider usage of products including these ingredients. The purpose of the study was to reveal consumers' perspectives on novel, and partly traditional but marginally utilized, ingredients to be used in regular cooking and their sensory characteristics and nutritional and environmental aspects. Consumer attitudes were obtained with two online consumer surveys. Consumer surveys revealed the most interesting ingredients. Plant-based ingredients are preferred over raw materials of animal or insect origin and these are also perceived as more pleasant. Plants were also regarded as credible, ecological, natural, healthy and nutrient-rich. Finnish consumers are not ready to adopt insects into their diet. Neither synthetic meat nor three-dimensional printed food have potential without further knowledge or experience of consumers. Findings of this research give baseline information on consumer attitudes towards novel ingredients. Further research is needed to investigate the perceived pleasantness when the potential ingredients are tasted.

Apple pomace as food fortification ingredient: A systematic review and meta-analysis

The present review aimed to investigate and analyze the use of byproduct apple pomace as a fortification ingredient in different types of foods. The data obtained from English published articles found on Web of Science, Scopus, and Google Scholar in the period from 2007 to 2019 were used for making the table overview and meta-analysis of results described in those studies. The systematic review confirmed the importance of apple pomace use in the food industry due to the beneficial nutritional profile and ecological issue (waste management). The main attributes of apple pomace are high content of antioxidant compounds and dietary fibers. Dietary fibers from apple pomace significantly increased total fiber content in enriched products-meaning that the transfer of the fortification can be declared health beneficial. The conducted meta-analysis showed unambiguously the different influence of apple pomace addition according to fortified food commodity. The fortification drawbacks were noticeable in plant food products because darker and brownish color was not evaluated positively by panelists. Oppositely, color, as one of the main sensory characteristics, was beneficially affected in animal origin food. The sensory properties, including color, play an important role in product acceptance by consumers. Besides color, animal origin products fortified by apple pomace showed the most acceptable textural properties and oxidative stability.

Dietary Fiber from Underutilized Plant Resources—A Positive Approach for Valorization of Fruit and Vegetable Wastes

Agri-food industries generate enormous amounts of fruit and vegetable processing wastes, which opens up an important research area aimed towards minimizing and managing them efficiently to support zero wastes and/or circular economy concept. These wastes remain underutilized owing to a lack of appropriate processing technologies vital for their efficient valorization, especially for recovery of health beneficial bioactives like dietary fibers. Dietary fiber finds wide applications in food and pharmaceutical industries and holds high promise as a potential food additive and/or as a functional food ingredient to meet the techno-functional purposes important for developing health-promoting value-added products. Based on this, the present review has been designed to support ‘zero waste’ and ‘waste to wealth’ concepts. In addition, the focus revolves around providing updated information on various sustainability challenges incurred towards valorization of fruit and vegetable wastes for extraction of health promoting dietary fibers.

Thymus algeriensis Bioss & Reut: Relationship of phenolic compounds composition with in vitro/in vivo antioxidant and antibacterial activity

Thymus algeriensis Bioss & Reut is an Algerian native plant traditionally used for culinary and medicinal purposes. To evaluate the in vivo antioxidant and antimicrobial properties of T. algeriensis, phenolic compounds were extracted using hydromethanolic solutions and administrated to Swiss albinos mice. It was observed that the plasma antioxidant capacity increased, as well as catalase and glutathione levels, whereas malondialdehyde decreased. In vitro assays confirmed that the extract scavenged 2,2-diphenyl-1-picrylhydrazyl, DPPH^• (7 µg/mL), chelated (EC₅₀: 512 µg/mL) and reduced iron ions (5.3 mM FeSO₄/g), and inhibited β-carotene bleaching (90% at 2 mg/mL). Antibacterial effects were also observed towards Salmonella typhimurium and Proteus mirabilis. However, the methanolic fraction obtained by reversed solid phase cartridge, showed antibacterial activity against Escherichia coli (MIC = 9.37 mg/mL), Proteus mirabilis (MIC = 4.68 mg/mL), Salmonella typhimurium (MIC = 7.06 mg/mL), Micrococcus luteus (MIC = 7.03 mg/mL), and Bacillus cereus (MIC = 2.34 mg/mL). UHPLC-DAD-ESI-MSⁿ analysis showed that these properties could result from rosmarinic acid, caffeoyl rosmaniric acid, and kaempferol and eriodictyol glycoside derivatives. These results pave the way for the understanding of T. algeriensis traditional applications and its use for the development of novel food applications.

Bioactivity and Sensory Properties of Probiotic Yogurt Fortified with Apple Pomace Flour

To meet the demand for new functional foods in line with the trend of sustainable development, a novel probiotic yogurt fortified with 1%, 3%, and 5% apple pomace flour (APF) added immediately after inoculation with Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium bifidum was developed. Upon fermentation in the presence of APF, a number of probiotic strains remained within the required range, while the syneresis of enriched yogurts was reduced up to 1.8 times in comparison to the control. Supernatants (i.e., extracted whey) obtained from yogurts with 1%, 3%, and 5% APF respectively had 1.4-, 1.8-, and 2.3-fold higher total phenolic content (TPC) than the control, 3.3-, 4.7-, and 8.0-fold higher radical scavenging (DPPH), and 1.3-, 1.6-, and 1.7-fold higher reducing activity (FRAP). Also, probiotic yogurt supernatants (3% and 5%) inhibited colon cancer cells’ viability (HCT 116, 12% and 17%; SW-620, 13% and 19%, respectively). The highest firmness, cohesiveness, and viscosity index values, and the highest scores for color and taste, were obtained for yogurt with 3% APF, indicating that this is the optimal APF amount for the production of novel yogurt with functional properties.

Changes in 3-, 2-Monochloropropandiol and Glycidyl Esters during a Conventional Baking System with Addition of Antioxidants

Shortening derived from palm oil is widely used in baking applications. However, palm oil and the related products are reported to contain high levels of monochloropropandiol (MCPD) ester and glycidyl ester (GE). MCPD and glycidol are known as process contaminants, which are carcinogenic and genotoxic compounds, respectively. The objective was to evaluate the effects of antioxidant addition in palm olein and stearin to the content of MCPD esters and GE in baked cake. Butylated hydroxyanisole (BHA), rosemary extract and tocopherol were used to fortify the samples at 200 mg/kg and in combinations (400, 600 and 800 mg/kg rosemary or tocopherol combined with 200 mg/kg BHA). The MCPD esters and GE content, radical formation and the quality of the fats portion were analyzed. The results showed that palm olein fortified with rosemary extract yielded less 2-MCPD ester. The GE content was lower when soft stearin was fortified with rosemary. ESR spectrometry measurements showed that the antioxidants were effective to reduce radical formation. The synergistic effects of combining antioxidants controlled the contaminants formation. In conclusion, oxidation stability was comparable either in the single or combined antioxidants. Tocopherol in combination with BHA was more effective in controlling the MCPD esters and GE formation.

Investigation of Total Phenolic Content and Antioxidant Activities of Spruce Bark Extracts Isolated by Deep Eutectic Solvents

Extracts from spruce bark obtained using different deep eutectic solvents were screened for their total phenolic content (TPC) and antioxidant activities. Water containing choline chloride-based deep eutectic solvents (DESs) with lactic acid and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol, with different molar ratios, were used as extractants. Basic characteristics of the DESs (density, viscosity, conductivity, and refractive index) were determined. All the DESs used behave as Newtonian liquids. The extractions were performed for 2 h at 60 °C under continuous stirring. TPC was determined spectrophotometrically, using the Folin-Ciocalteu reagent, and expressed as gallic acid equivalent (GAE). The antioxidant activity was determined spectrophotometrically by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The TPC varied from 233.6 to 596.2 mg GAE/100 g dry bark; radical scavenging activity (RSA) ranged between 81.4% and 95%. This study demonstrated that deep eutectic solvents are suitable solvents for extracting phenolic compounds from spruce bark.

Fruit Seeds as Sources of Bioactive Compounds: Sustainable Production of High Value-Added Ingredients from By-Products within Circular Economy

The circular economy is an umbrella concept that applies different mechanisms aiming to minimize waste generation, thus decoupling economic growth from natural resources. Each year, an estimated one-third of all food produced is wasted; this is equivalent to 1.3 billion tons of food, which is worth around US$1 trillion or even $2.6 trillion when social and economic costs are included. In the fruit and vegetable sector, 45% of the total produced amount is lost in the production (post-harvest, processing, and distribution) and consumption chains. Therefore, it is necessary to find new technological and environmentally friendly solutions to utilize fruit wastes as new raw materials to develop and scale up the production of high value-added products and ingredients. Considering that the production and consumption of fruits has increased in the last years and following the need to find the sustainable use of different fruit side streams, this work aimed to describe the chemical composition and bioactivity of different fruit seeds consumed worldwide. A comprehensive focus is given on the extraction techniques of water-soluble and lipophilic compounds and in vitro/in vivo functionalities, and the link between chemical composition and observed activity is holistically explained.