Evaluation of physical parameters and spectral characterization of the quality of soaps containing by-products from the food industry

The present study investigated several properties such as friction, hardness, penetration work, and cutting forces in soaps formulated with apple and carrot pomace at varying concentrations of 5%, 10%, and 15%. To gain insights into the molecular-level alterations within the formulated soap samples, they were spectroscopically analyzed using Fourier-transform infrared spectroscopy. The sliding friction analyses revealed that the investigated extrudate additives had no significant impact on the frictional forces of the soaps. However, notable differences were observed in the cutting force, hardness, and penetration work between the control and pomace-added samples. Excluding the control samples, no statistically significant distinctions were found between the cutting force, hardness, and work of penetration of soaps containing apple pomace and carrot pomace. Moreover, the quantity of pomace incorporated did not induce any significant variations in the results. The obtained samples were characterised at the molecular level using FTIR Fourier transform infrared spectroscopy. On the other hand, alterations in band intensities suggested improved molecular packing of the compounds within the samples due to the presence of the additives.

Production of buns, the bakery-based snack food, with reduced refined wheat flour content: Recent developments

Buns are very soft puffed bakery snack items, popular in many countries, especially low- and middle-income nations. Buns are either eaten directly or used in the preparation of culinary items. Buns are mainly prepared using refined wheat flour rich in gluten protein and devoid of husk. Consuming gluten-containing foods is leading to several health complications among consumers worldwide. Hence, several researchers have tried to reduce the gluten content in the dough by incorporating cereals flours, protein-rich sources like soy, cheese whey, etc., hydrocolloids, millets, pomace, and seed flour of vegetables and fruits, etc. These additives not only reduce gluten content in the buns to a certain extent but also enhance the fibre content and nutritional profile of the buns. This mini-review summarizes the recent developments in the production of buns using these additives to improve their nutritional quality.

Preservation of white wine pomace by high hydrostatic pressure

The effect of different high hydrostatic pressure (HHP) treatments (400, 600 MPa for 1, 6 min) on white wine pomace was studied throughout storage conditions (270 days) at different temperature conditions (4° and 20 °C). The final use of this product would be as an ingredient for food products preservation. Microbiological, enzyme and physico-chemical parameters were evaluated after processing and during storage. HHP greatly reduced the microbial counts of treated pomace and allowed obtaining a safe product with a long shelf-life at 4 and 20 °C. The HHP treatment also preserved phenolic compounds content, however an important reduction of these compounds was found during storage since the polyphenol oxidase enzyme remained active after the treatment and during storage. Phenolic compounds were better preserved during storage at 4 °C than at 20 °C. The application of HHP at 600 MPa/6 min and the refrigeration of the treated pomace would allow obtaining a microbiologically safe pomace with high levels of phenolic compounds with a shelf-life of 90 days. The activity of the enzyme should be limited in future to ensure a long shelf-life of the processed pomace.

Utilization of bottle gourd (Lagenaria siceraria (Mol.) Standl.) pomace for the preparation of instant kheer (dessert) mix

Bottle gourd pomace, a waste from vegetable processing industry was used to prepare instant kheer (dessert) mix. In this study, the bottle gourd was procured from the farm, washed, grated, steam blanched and the grits were further divided into two parts. One part of grits was dried without juice extraction (BGFD- Bottle gourd fresh dried), while, the other half (BGPD- Bottle gourd pomace dried) was dehydrated after extraction of juice. The dehydrated grits were used for the preparation of kheer mix and the recipe was optimized using RSM Central Composite Design (CCD). The variables were BGFD and BGPD ranged 3-7 g. The other ingredients with the fixed quantities were milk powder (50 g), sugar (15 g), and small cardamom (1 g). The product was selected based on sensory responses like taste, colour, flavour, texture, and overall acceptability (OAA). The software suggested a kheer mix prepared using 7 g BGFD and 3 g BGPD will produce the best sensory scores. The prepared kheer mix had a moisture, TSS, carbohydrates, reducing sugars, total sugars, titratable acidity, crude protein, and crude fat content of 7.9%, 27 °B, 72.21%, 10.79%, 16.75%, 0.896% CA, 10.76%, and 7.63%, respectively. The product was rich in energy (400.55 kcal/100 g), total phenols (4.99 mg/100 g), and exhibited strong antioxidant activity (46%). The total plate count on the product on nutrient agar medium was 4.3 × 106 CFU/g. The kheer could be prepared by adding 140 mL of water to 70 g of water to kheer mix and cooking it for 10 min. Further, to see the credibility and obtain more clearer patterns, the Canonical Correlation Analysis (CCA) and Principal Component Analysis (PCA) were applied. The overall variation of the BGFD and BGPD on the sensory parameters based on canonical correlation analysis was 92.5%. The sum of Principal Components PC1 and PC2 explained a very high variability (98.2%) among the studied treatments.

Quantitative metabolomic analysis reveals the fractionation of active compounds during lemon fruit juicing

In this study, metabolomic analysis was employed to investigate the separation (fractionation) of active compounds into lemon juice (LJ) and lemon pomace (LP) during lemon juicing. A total of 968 metabolites were identified, and 438 differentially abundant metabolites (DAMs) were screened out between LJ and LP, suggesting significant metabolite fractionation during juicing. The "flavonoids", "phenolic acids", and "saccharides and alcohols" were mainly retained in the LP, while the fractionation of major "organic acids" was differentiated. Seven of the 12 potential bitter metabolites were more abundant in the LP and two were more abundant in the LJ, suggesting that LP would be more bitter. L-Ascorbic acid, thiamine, and acitretin were significantly lost during juicing, while riboflavin was newly dissolved during juicing. The antioxidant capacity of LP was significantly higher than that of LJ, which was closely related to the higher abundance of phenolic acid metabolites in LP. These findings suggtested that promoting the release of flavonoids and phenolic acids from LP is a potential strategy to improve the quality of LJ. Results also provides important information and reference for developing high-value products by using LP.

Upcycling of black currant pomace for the production of a fermented beverage with Wolfiporia cocos

Pomace as a side stream from black currant juice production is mostly discarded, even though it is rich in nutrients like protein, fiber, sugars, anthocyanins, polyphenols, and other secondary metabolites. Fungi from the division of Basidiomycota have a great enzymatic toolbox to recycle these complex mixtures of nutrients. In particular, the edible medicinal fungus Wolfiporia cocos has been described as a suitable biocatalyst to form pleasant aroma compounds in fermentation processes. Therefore, medium optimization, upscaling, and filtration were performed to produce a beverage based on black currant pomace fermented with W. cocos. A trained panel described the beverage as highly pleasant, reminiscent of honey, flowers and berries with a well-balanced sour and sweet taste. The flavor compounds linalool (citrus), geraniol (flowery), phenylacetic acid (honey), methyl phenylacetate (honey), eugenol (clove), and 2-phenylethanol (rose) were produced during fermentation and the concentrations exceeded their respective odor thresholds. The produced beverage was evaluated with 8.0 ± 1.4 from 10 for the question of whether panelists would buy the product. Fungal fermentation with the edible fungus W. cocos enabled the production of a highly pleasant beverage and additionally may reduce waste by using pomace and table sugar as sole ingredients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05677-4.

Identification of polyphenols from Rosa roxburghii Tratt pomace and evaluation of in vitro and in vivo antioxidant activity

Rosa roxburghii Tratt pomace (RRTP) has increasingly attracted attention due to its various nutritional ingredients and health benefits. In this study, the free phenolic fraction (RRTP-FPF) and bound phenolic fraction (RRTP-BPF) were extracted from RRTP by solvent extraction method and alkaline hydrolysis method, respectively. The composition of polyphenols in RRTP-FPF and RRTP-BPF were identified by ultra-high performance liquid chromatography equipped with an electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS/MS). In vitro antioxidant assays indicated that RRTP-FPF and RRTP-BPF could scavenge radicals in a dose-dependent manner, and RRTP-BPF exhibited better scavenging activity than RRTP-FPF. In addition, RRTP-FPF and RRTP-BPF (20 ∼ 100 μg/mL) treatment for 24 h could significantly increase the survival rate and decrease reactive oxygen species (ROS) level of paraquat-exposed nematodes through improving the activities of superoxide dismutase (SOD) and catalase (CAT). These results suggest that RRTP could be as a good and cheap source of natural antioxidants.

Comparative elucidation of colour, volatile and phenolic profiles of black carrot (Daucus carota L.) pomace and powders prepared by five different drying methods

Black carrot pomace is a juice industry by-product that can be easily spoiled due to its high moisture content and usually considered as waste; however, it is a valuable product with high amount of bioactive compounds that can be recovered for further application in several industrial fields. Drying is an effective method for the preservation of this product. Thus, the influence of five drying methods (FD: freeze drying, MWD: microwave drying, CD: convective drying, VCD: vacuum/convective drying, CHD: conductive hydro drying) on colour, phenolics and volatiles of pomace were investigated. Findings revealed that drying process decreased the amount of anthocyanins, colourless phenolics and volatile compounds. CHD resulted in similar colour quality and yielded a better preservation of colour and phenolics while FD provided dried sample with an aroma quality similar to fresh sample. The shorter duration of the CHD makes it a better choice.

Influence of genetic and interannual factors on bioactive compounds of olive pomace determined through a germplasm survey

Olive mill wastes, generated in the extraction of virgin olive oil (VOO), are of important concern for the industry owing to the produced volume and polluting load, mainly associated with the presence of organic compounds. Among them, it is worth mentioning bioactive compounds, mainly phenols and triterpenes, which could be potentially isolated for further use in the cosmetic, pharmaceutical, or food industries. This research analyzed the olive pomace after extraction of VOO from fruits harvested of 43 international olive cultivars during three consecutive seasons. The cultivar was identified as the most determinant factor to explain the variability in the relative concentration of phenols and terpenic acids in the extracts. In addition, the characterization of olive pomace extracts allowed clustering cultivars according to the profile of bioactive compounds. Finally, we identified the components responsible for the observed discrimination that was explained according to biosynthetic metabolic pathways.

Effect of heat processing on phenolics and their possible transformation in low-sugar high-moisture (LSHM) fruit products from Kainth (Pyrus pashia Buch.-ham ex D. Don) fruit

LSHM fruit products were developed using 40% Kainth fruit juice (KJ40) and 10% pomace (KP10). The percentage of fruit juice and pomace was optimized based on the sensory analysis. The effect of heat processing on the nutritional and neutraceuticals parameters was studied. The product KJ40 was rich in free phenolics, while in KP10, it was bound phenolics. Both the products had good retention of phenolics, vitamins, minerals during processing and were microbiologically safe for up to six months. UPLC-ESI-HRMS was used for the identification and quantification of major phenolic compounds. Arbutin and catechin were the most stable phenolics during processing and storage. A slight change in catechin and chlorogenic acid contents was observed, which might be transformed or degraded. Tentatively, three unknown compounds were also identified using non-targeted analysis (Marker View Software, AB Sciex). Both products might offer health benefits as rich in phenolics and dietary fiber (≥5%).

Varietal influence on phenolic constituents and nutritive characteristics of pomace obtained from apples grown in western Himalayas

Apple fruit processing is not variety specific in India, which affect the overall quality of the final processed product. The present study was aimed at elucidation of the nutritive value, phenolic content, antioxidant activity and bioactive phenolic constituents of five widely used apple varieties (Royal Delicious, Red Delicious, Golden Delicious, Red Chief and Red Gold) of western Himalayas. The pomace obtained from different varieties was evaluated to assess the fruit quality. Royal Delicious pomace had significantly high (p < 0.05) total dietary fibre content (42.63 ± 1.26%) together with soluble (8.25 ± 0.95%) and insoluble fibre (32.90 ± 0.89%), as compared to other apple varieties. The pomace samples were extracted with 70% aqueous methanol to obtain polyphenol enriched extracts. The results of Folin-Ciocalteau assay showed that hydroalcoholic extract of Royal Delicious pomace exhibit higher phenolic content as compared to other varieties and ranged between 2.19 ± 0.09 and 4.59 ± 0.47 mg GAE/g. Royal Delicious pomace also possess higher antioxidant capacity i.e. 3.35 ± 0.10 mg/g, 2.71 ± 0.10 mg/g and 4.67 ± 0.03 mg/g as measured by DPPH, ABTS free radical scavenging assay and FRAP reducing assay, respectively. The higher phenolic content in Royal Delicious pomace was also confirmed by RP-HPLC-DAD analysis. Results of HPLC analysis revealed the presence of phloridzin (487.07 ± 0.04 µg/g), quercetin (241.18 ± 0.03 µg/g), quercitrin (178.34 ± 0.02 µg/g) and quercetin-3-glucoside (195.21 ± 0.05 µg/g) as major constituents. Present results indicate that Royal Delicious variety is rich in dietary fibre and phenolic compounds that might be used by the food sector as a source of bioactive health promoting constituents/dietary supplements.

Protective effect of Pinot noir pomace extract against the cytotoxicity induced by polycyclic aromatic hydrocarbons on endothelial cells

Polycyclic Aromatic Hydrocarbons (PAHs) are pollutants found in the air generated mainly by the combustion of coal or biomass burning. Exposure to Polycyclic Aromatic Hydrocarbons is positively correlated with cardiovascular diseases. Phenolic compounds are widely found in the plant kingdom, and their availability from agri-food processing waste has led to an increased interest in their recovery. The production of large amounts of organic waste created by the wine industry has emphasized the valuation of these wastes to generate high-added-value by-products. The objective of this work was to investigate the protective effect of Pinot noir pomace extract on human endothelial cells against PAHs found in the polluted air of Temuco, Chile. The pomace extract was characterized by spectrophotometric analysis and high-performance liquid chromatography (HPLC). Results revealed the presence of 5 glycosylated anthocyanins and 9 low molecular weight polyphenols. Molecular docking indicated that cyanidin-3-glucoside (-9.2 kcal/mol) and quercetin (-9.6 kcal/mol) had the highest affinities for the Nrf2 binding site in the Keap1 protein, suggesting a possible competition with this transcription factor. Endothelial cells from the human umbilical vein were exposed to increasing concentrations of Phenanthrene, Fluoranthene, and Pyrene diluted in DMSO in a ratio of 3:1:1 (10 μM-200 μM). Viability through the MTS assay showed that 150 μM of PAHs was sufficient to reduce viability by 75% (p ˂ 0.0001). When the cells were pre-treated with 400 μg/ml of the extract, 150 μM of PAHs did not exert cell death (80% viability). Our preliminary results show that polyphenolic components found in Pinot noir pomace might have a beneficial effect as a protective agent.

The influence of the extrusion process on the nutritional composition, physical properties and storage stability of black chokeberry pomaces

The study examined the influence of the process of extrusion on the physical properties and nutritional composition of black chokeberry pomaces. It has been determined that the extrusion process resulted in a reduction of the content of anthocyanins and fibre, but an increase of the contribution of simple sugars. In order to assess the phase transitions occurring in the products, a state diagram was utilized, which was constructed using the freezing and vitrification curve and values characterizing the conditions of maximum cryoconcentration. The determined values of critical water activity (based on water activity concepts) indicate that pomaces and extrudates retain crispiness in storage under moderate environmental relative humidity conditions. However, in the case of the glass transition concept, the determined values of water activity indicate that products stored in room temperature must be protected against the influence of humidity.

Phenolic profile, in vitro antimicrobial activity and antioxidant capacity of Vaccinium meridionale swartz pomace

Berries of Vaccinium meridionale Swartz contain a variety of phytochemicals, which are believed to account for their bioactive properties. The potential of Vaccinium meridionale Swartz pomace as a source of bioactive compounds was investigated. The dietary fiber (DF) content was assessed by the AOAC method, phenolic compounds were characterized and quantified via HPLC-PDA and UPLC-QTOF-MS. The in vitro antibacterial activity was tested against Gram-positive and Gram-negative bacteria. The antioxidant properties were assessed by the ORAC and the ABTS assays. The DF content was 52.4 ± 3.7%, phenolic compounds comprised anthocyanins (ACNs) (747.6 ± 167.5 mg cyanidin-3-glucoside/100 g FW), hydroxycinammic acids (HCAs) (229.2 ± 68.4 mg chlorogenic acid equivalents/100 g FW), flavonols (335.0 ± 139.5 rutin equivalents/100 g FW), and procyanidins (PACs) (140.9 ± 33.3 mg cocoa procyanidin equivalents/100 g FW). Staphylococcus aureus was more sensitive than E. coli. The ORAC value was 250.0 ± 32.0 μmol TE/g fresh weight (FW). Results suggest that the residue from V. meridionale S. can be utilized to obtain valuable nutraceuticals for the development of functional foods.

Phenolic composition and antioxidant activities of saskatoon berry fruit and pomace

Total phenolic chromatographic indices (TPCI) of three commercially grown saskatoon berry varieties and a pomace from commercial juice production were determined. Northline was shown to have the highest TPCI of 504.2 mg/100 g FW. These results agreed with total phenolic content results for these varieties. The TPCI of the commercial pomace was 404.2 mg/100 g pomace indicating that a significant concentration of phenolics were present in this co-product, showing the commercial relevance of this material. A phenolic rich extract (PRE; 500 ppm) of the Northline variety was compared to BHT (0.02% w:w) and Rosamox (0.2% w:w) for delaying the oxidation of borage oil via rancimat analysis. Induction times were 1.46 h (borage oil), 1.44 h (Rosamox), 2.18 h (BHT), and 2.42 h (PRE), which was a ∼65% delay in the oxidation of borage oil. These results clearly support the value of this material as an antioxidant ingredient in foods, pharmaceuticals, nutriceuticals and cosmetics.

Effects of apple, orange and carrot pomace powders on gluten-free batter rheology and cake properties

This study examined the effects of using different fiber sources [apple pomace powder (APP), carrot pomace powder (CPP) and orange pomace powder (OPP)] on batter rheology and quality characteristics of rice flour-based gluten-free cakes. Gluten-free cake batters were formulated by replacing different amounts of rice flour (0, 5, 10, and 15%) with APP, CPP, and OPP. As a control cake, batters containing no pomace powder were used. The flow behaviors and viscoelastic characteristics of dietary fiber-enriched cake batters were investigated. All cake batters showed shear thinning behavior and the Power Law model was found to explain the flow behavior of all batter formulations. Apparent viscosity, elastic modulus (G'), and viscous modulus (G″) of the batter increased with increasing pomace powder content. Furthermore, addition of pomace powder increased batter specific gravity and crumb hardness, and decreased specific volume of cakes. Cakes containing 5% OPP had similar volume index and hardness values to the control sample. The sensory properties of the cake samples were investigated concerning color, texture, appearance, flavor and overall acceptability, and those with 5% OPP received the highest acceptance scores from the panelists.

Olive pomace as a valuable source of bioactive compounds: A study regarding its lipid- and water-soluble components

Olive pomace is a major output of olive oil processing. This by-product is a valuable source of bioactive compounds with well-recognized benefits for human health and well-being. In this work, the proximate composition and the profiles of vitamin E (HPLC-DAD-FLD), fatty acids (GC-FID) and phenolics (HPLC-DAD-FL/MSⁿ) were determined. Additionally, a sustainable process for antioxidants extraction - Multi-frequency Multimode Modulated (MMM) ultrasonic technique - was compared to a conventional solid-liquid extraction. The total phenolics content and antioxidant activity (ferric reducing antioxidant power and DPPH scavenging ability) of the extracts were analysed to assess the efficacy of both extraction methodologies. The vitamin E profile of the olive pomace comprised the vitamers α-tocopherol, β-tocopherol, α-tocotrienol and γ-tocopherol. α-Tocopherol was the major form (2.63 mg/100 g), while the other vitamers were present in amounts lower than 0.1 mg/100 g. The lipid fraction was especially rich in oleic acid (75%), followed by palmitic (10%), linoleic (9%), and stearic (3%) acids. Hydroxytyrosol and comsegoloside represented ≈79% of the total phenolics present in olive pomace. Hydroxytyrosol content was 83.6 mg/100 g, while tyrosol was present in lower amounts (3.4 mg/100 g). Concerning the antioxidants extraction, the MMM technique allowed a faster and higher recovery (p < 0.05) of the compounds, compared to the conventional solid-liquid extraction. By this way, it seems to be a very promising eco-friendly and effective methodology to extract antioxidants from this and other matrices.

Pomace limits tannin retention in Frontenac wines

The impact of different factors (must protein treatment: bentonite and heat; pomace: fermented with and without; tannin addition: 0-9 g/L; and time of maceration: 0-11 days) on tannin, pigment, and protein extraction/retention in Frontenac wines was investigated. Wine tannin concentration and composition were determined by HPLC-fluorescence. Protein and pigment parameters were analysed by BCA assay and Boulton's method, respectively, using UV-spectrophotometry. Results: Bentonite and heat significantly reduced wine protein concentration at the end of alcoholic fermentation but heat was less efficient than bentonite (1.8-5.0 times less). Removing wine proteins did not improve tannin retention in wines (p > 0.1032) but fermenting without pomace significantly improved their retention (up to 2.4 times), especially that of polymeric flavan-3-ols (up to 27.8%). An addition of 3 g/L of enological tannins in wines, fermented with or without pomace, was necessary to increase wine tannin concentration significantly.

Effect of dose, contact time and varietal origin on the final wine phenolic composition

Fining, which involves the addition of adsorptive material in order to reduce or eliminate certain unwanted components, is a common winemaking practice. Fining agents affect the wine phenolic compounds, some of which may be reduced. When this reduction is experimented by the tannins, a positive effect may result by decreasing astringency in the wine, although a decrease in the wine color may also take place when the anthocyanins are involved, affecting its quality. Recently, grape cell wall material has been tested as a potential fining agent in wines, since it shows a high affinity for tannins so that its use could reduce wine astringency. In this work, the use of purified grape pomace as fining agent is proposed and the effect of different doses and contact times on wine chromatic characteristics was investigated as well as how differences in the composition of the purified pomace could alter the phenolic composition of a red wine. The results showed that a Monastrell purified grape pomace dose of 6 mg/ml and a contact time of 5 days could be suitable for decreasing the wine tannin content without producing great changes in the wine chromatic characteristics. When comparing the effect of purified pomaces from four grape varieties, some differences in their capacity to interact with the wine tannins and anthocyanins were found, however, the results confirm that the purified grape pomace, a byproduct of the enology industry could be a new interesting fining material.

Antimicrobial protection of minced pork meat with the use of Swamp Cranberry (Vaccinium oxycoccos L.) fruit and pomace extracts

The objective of the study was to determine the antimicrobial activity of Swamp Cranberry (Vaccinium oxycoccos) fruit and pomace extracts (FSCE and PSCE) and their efficiency in minced pork meat. Ethanol (96 and 40%) and water were used for raw material extraction. Organic acids, flavonols, terpenes and stilbenes composition of the extracts was determined using HPLC. Minimal inhibitory concentration and minimum bactericidal/fungicidal concentration were determined for bacteria and fungi strains using the broth macrodilution method. The growth inhibition of Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli in inoculated fresh minced pork meat containing 2.5% we-PSCE or we-FSCE (prepared by using 40% ethanol) were evaluated within 6 days of refrigeration storage. Swamp Cranberry pomace extracts contained stilbenes and more organics acids and flavonols than fruit extracts. Extracts inhibited Gram-positive bacteria strains stronger than Gram-negative, regardless of used raw material. The extracts did not show antifungal activity. Water-ethanol extracts (we-FSCE and we-PSCE) had stronger antibacterial properties than ethanolic extracts (e-FSCE and e-PSCE) and aqueous extracts (w-FSCE and w-PSCE). A 2.5% addition of we-PSCE or we-FSCE to minced pork meat resulted in a reduction of the number of pathogenic cells by 4 log cycles after 4 days of refrigeration storage. Baked burgers containing 2.5% of these extracts obtained high ratings for color, taste, odor, juiciness, and overall acceptability that did not differ statistically from control samples. Extracts from Swamp Cranberry constitute interesting candidates for natural preservatives of minced pork meat.

Production of pectinases for quality apple juice through fermentation of orange pomace

Production of pectinases by Aspergillus niger was successfully carried out through solid state fermentation. Orange pomace was used as substrate to produce pectinases using a wild type of A. niger isolated from a rotten orange texture. Some of the important parameters affecting exo- and endo-pectinases activities such as temperature, moisture, C/N ratio were optimized. The results indicated that the produced pectinases exhibited maximum activity in temperature range of 45-55 °C and the maximum enzyme productivity occurred at 70% moisture content and C/N ratio of 10. The enzyme kinetic was studied using Michaelis-Menten and Logistic model and the equation were fitted to experimental data for both exo- and endo-pectinases activities. In evaluation of kinetic model, it was found that Monod model presented perfectly fitted with experimental data. Monod kinetic parameters [Formula: see text] for exo-pectinase activities were [Formula: see text] mM, respectively. The Monod kinetic parameters [Formula: see text] for endo-pectinase activity were [Formula: see text] and [Formula: see text] respectively. Finally, the performances of the produced pectinases were evaluated on natural apple juice. It was confirmed that concentration of soluble sugar, clarity and viscosity of the juice and the yield of extracted juice were significantly improved by the enzymatic hydrolysis activity of pectinases.

Effect of pre-treatment of blue honeysuckle berries on bioactive iridoid content

The aim of the study was to evaluate the effect of the different methods of preparation of the blue honeysuckle (Lonicera caerulea L. var. Kamtschatica) cv. 'Wojtek' and their influence on the iridoid content of fruit juices and fresh and freeze-dried pomaces. Compounds were identified by UPLC-ESI-qTOF-MS/MS in negative ion mode. Five iridoids - loganic acid, 7-epi-loganic acid 7-O-pentoside, loganin, sweroside, and secologanin - were determined in blue honeysuckle fruits and products. The results revealed no differences in iridoid content between the fresh pomace from skin and flesh, or between the juice from skin and flesh. A higher content of iridoids was obtained in juice from crushed than from whole berries, and in freeze-dried pomace from whole than from crushed berries. Freeze-dried pomace from blue honeysuckle can be an excellent source of bioactive iridoids.

Influence of juice processing factors on quality of black chokeberry pomace as a future resource for colour extraction

Aronia melanocarpa berries are a rich source of anthocyanins and its pomace, a by-product of juice processing, could be efficiently used for extraction of natural colours for the food industry. This study evaluated the influence blanching, freezing, maceration temperatures (2°C, 50°C) and enzyme treatments before juice pressing on the yield and anthocyanin composition of both juice and pomace. Total anthocyanin levels in pomace were affected mostly by enzyme treatment followed by maceration temperature. The pre-heating of the mash prior to processing increased juice yield and retention of anthocyanins in the pomace. Cold maceration of frozen berries without enzyme addition gave the highest concentrations of anthocyanins in the pomace, and both cold and hot maceration of fresh unblanched berries with enzyme the lowest. The results support future exploitation of natural colours from pomace side streams of Aronia, thus increasing competitiveness of Aronia berry production.

Valorisation of raspberry and blueberry pomace through the formulation of value-added gluten-free cookies

Successful valorisation of raspberry and blueberry pomace was achieved through their application, as dried and ground powders, in the formulation of value-added gluten-free cookies. Simplex-lattice mixture design approach was applied to obtain the product with the best sensory properties, nutritional profile and antioxidant activity. The highest desirability of 90.0 % was accomplished with the substitution of gluten-free flour mixture with 28.2 % of blueberry and 1.8 % of raspberry pomace. The model was verified. Optimized cookies had similar protein (3.72 %) and carbohydrate (66.7 %) contents as gluten-containing counterparts used for comparison, but significantly lower fat content (10.97 %). Daily portion of the optimized cookies meets: 5.00 % and 7.73 % of dietary reference intakes (DRIs) for linoleic acid, 23.6 % and 34.3 % of DRIs for α-linolenic acid and 10.3 % and 15.6 % of DRIs for dietary fibers, for male and female adults, respectively. The nutritional profile of the optimized formulation makes it comparable with added-value gluten-containing counterparts.

The effects of strawberry, black currant, and chokeberry extracts in a grain dietary fiber matrix on intestinal fermentation in rats

The objective of this work was to study the composition, hydration properties and oil holding capacity, antioxidant properties and the physiological effects on the digestive system of dietary preparations containing wheat or oat fiber enriched with polyphenol extracts from strawberry, chokeberry, and black currant pomace. By the addition of black currant, strawberry and chokeberry polyphenol extracts to grain fibers preparations with corresponding polyphenol content of 0.7%-0.8%, 1.1%-1.2%, and 2.5%-2.9% were obtained. The preparations were used as part (8%) of a modified AIN-93 diet given to growing Wistar rats (8 animals per group) over a period of 4weeks. The highest antioxidant potential had grain-chokeberry preparations with the greatest polyphenol content, while grain-black currant preparations exhibited the lowest antioxidant potential with the smallest polyphenol content. The addition of strawberry and chokeberry extracts caused a decrease in the activity of bacterial β-glucosidase and α-galactosidase, while black currant extract led to increased activity of β-galactosidase and β-glucuronidase. The production of short chain fatty acids (SCFAs) in the caecum of rats fed the grain-strawberry preparation, rich in ellagitannins, was considerably higher than the grain-black currant preparation, rich in proanthocyanidins and anthocyans, or the grain-chokeberry preparation with the highest polyphenol content (78.3 vs. 64.7 vs. 56.3μmol/100g body weight, p=0.012). In comparison to preparations without polyphenols only chokeberry extract significantly decreased SCFA concentration. The grain-strawberry preparations were characterized by a higher antioxidant potential per unit of polyphenol content and exhibited a more beneficial influence on the fermentation processes in the caecum of rats than the grain-black currant and grain-chokeberry preparations.

Chemical composition, functional properties and processing of carrot-a review

Carrot is one of the important root vegetables rich in bioactive compounds like carotenoids and dietary fibers with appreciable levels of several other functional components having significant health-promoting properties. The consumption of carrot and its products is increasing steadily due to its recognition as an important source of natural antioxidants having anticancer activity. Apart from carrot roots being traditionally used in salad and preparation of curries in India, these could commercially be converted into nutritionally rich processed products like juice, concentrate, dried powder, canned, preserve, candy, pickle, and gazrailla. Carrot pomace containing about 50% of β-carotene could profitably be utilized for the supplementation of products like cake, bread, biscuits and preparation of several types of functional products. The present review highlights the nutritional composition, health promoting phytonutrients, functional properties, products development and by-products utilization of carrot and carrot pomace along with their potential application.