High pressure homogenization processing, thermal treatment and milk matrix affect in vitro bioaccessibility of phenolics in apple, grape and orange juice to different extents

Does hydration of 'Deglet Nour' date palm fruits improve their quality and help to reduce waste?

This work investigates the quality change of date palm fruits after hydration treatment which is commonly applied to enhance the hard textured 'Deglet Nour' fruits that are unacceptable for consumption. Date palm fruits were treated at 60-62 °C with saturated steam for 4 h in three different processing units (DPU). Mid Infrared Spectroscopy (MIR) giving a global spectral evaluation discriminates samples from the three DPUs and highlights date palm fruits of the first DPU regarding hydration treatment. Treatment led to a decrease of fruit firmness, skin lightness, and of sucrose and malic acid contents whereas citric acid and procyanidins contents and procyanidins 'degree of polymerization increased. Thermal treatment had no effect on glucose and fructose contents, on cell wall content and composition and on minor phenolic groups. Significant differences existed on dates from the three DPUs, discriminating dates presenting high firmness. Hydration treatment improve dates texture as expected while nutritional parameters were quite stable, confirming that is very promising and could be highly recommended to valorise fruit that are currently not commercialized. However, optimisation is needed for the very hard-type dates.

Conversion of gingerols to shogaols in ginger (Zingiber officinale roscoe) by puffing

Effect of puffing on conversion of gingerols to shogaols, physicochemical properties as well as antioxidant and anti-inflammatory activities of puffed ginger was investigated. Puffing significantly increased extraction yield and the highest value was 12.52% at 980 kPa. The significant decrease in gingerols and increase in shogaols were occurred after puffing, respectively. Especially, 6-shogaol was dramatically increased from 4.84 to 99.10 mg/g dried ginger. Puffed ginger exhibited the higher antioxidant activities (analyzed by DPPH, ABTS, TPC, and TFC) than those of control, and they were significantly increased with increasing puffing pressure. In case of anti-inflammatory activity, puffed ginger did not inhibit NO production, but significantly inhibited TNF-α and IL-6 productions. Among gingerols and shogaols, 6-shogaol showed significantly strong correlations with both antioxidant and anti-inflammatory activities. Consequently, puffed ginger can be applied to functional food industry, which dramatically increased the contents of 6, 8, 10-shogaols, the main bioactive compounds in ginger.

Roasted yerba mate (Ilex paraguariensis) infusions in bovine milk model before and after in vitro digestion: Bioaccessibility of phenolic compounds, antioxidant activity, protein-polyphenol interactions and bioactive peptides

Yerba mate is increasingly acknowledged for its bioactive properties and is currently being incorporated into various food and pharmaceutical products. When roasted, yerba mate transforms into mate tea, consumed as a hot aqueous infusion, and has gained popularity. This study investigated the bioaccessibility of phenolic compounds, protein-polyphenol interactions, antioxidant activity, and bioactive peptides in roasted yerba mate infusions, utilizing whole, semi-skimmed, and skimmed bovine milk models. The phytochemical profile of roasted yerba mate was analyzed in infusions with water and milk (whole, semi-skimmed, and skimmed), before and after in vitro digestion, identifying 18 compounds that exhibited variations in composition and presence among the samples. Bioavailability varied across different milk matrices, with milk being four times more efficient as a solvent for extraction. Gastric digestion significantly impacted (p < 0.05) the release of phenolic compounds, such as chlorogenic acid and rutin, with only chlorogenic acid remaining 100 % bioavailable in the infusion prepared with skimmed milk. Protein-polyphenol interaction did not influence protein digestion in different infusions, as there was a similarity in the hydrolysis pattern during the digestive process. Changes in antioxidant activity during digestion phases, especially after intestinal digestion in milk infusions, were related to alterations in protein structures and digestive interactions. The evaluation of total phenolic compounds highlighted that skimmed milk infusion notably preserved these compounds during digestion. Peptidomic analysis identified 253, 221, and 191 potentially bioactive peptides for whole, semi-skimmed, and skimmed milk-digested infusions, respectively, with a focus on anti-inflammatory and anticancer activities, presenting a synergistic approach to promote health benefits. The selection of milk type is crucial for comprehending the effects of digestion and interactions in bioactive compound-rich foods, highlighting the advantages of consuming plant infusions prepared with milk.

Bioavailability and mechanisms of dietary polyphenols affected by non-thermal processing technology in fruits and vegetables

Plant polyphenols play an essential role in human health. The bioactivity of polyphenols depends not only on their content but also on their bioavailability in food. The processing techniques, especially non-thermal processing, improve the retention and bioavailability of polyphenolic substances. However, there are limited studies summarizing the relationship between non-thermal processing, the bioavailability of polyphenols, and potential mechanisms. This review aims to summarize the effects of non-thermal processing techniques on the content and bioavailability of polyphenols in fruits and vegetables. Importantly, the disruption of cell walls and membranes, the inhibition of enzyme activities, free radical reactions, plant stress responses, and interactions of polyphenols with the food matrix caused by non-thermal processing are described. This study aims to enhance understanding of the significance of non-thermal processing technology in preserving the nutritional properties of dietary polyphenols in plant-based foods. It also offers theoretical support for the contribution of non-thermal processing technology in improving food nutrition.

Comparison of an Ultrasound-Assisted Aqueous Two-Phase System Extraction of Anthocyanins from Pomegranate Pomaces by Utilizing the Artificial Neural Network-Genetic Algorithm and Response Surface Methodology Models

As a by-product of pomegranate processing, the recycling and reuse of pomegranate pomaces (PPs) were crucial to environmentally sustainable development. Ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was applied to extract the anthocyanins (ACNs) from PPs in this study, and the central composite design response surface methodology (CCD-RSM) and artificial neural network-genetic algorithm (ANN-GA) models were utilized to optimize the extraction parameters and achieve the best yield. The results indicated that the ANN-GA model built for the ACN yield had a greater degree of fit and accuracy than the RSM model. The ideal model process parameters were optimized to have a liquid-solid ratio of 49.0 mL/g, an ethanol concentration of 28 g/100 g, an ultrasonic time of 27 min, and an ultrasonic power of 330 W, with a maximum value of 86.98% for the anticipated ACN yield. The experimental maximum value was 87.82%, which was within the 95% confidence interval. A total of six ACNs from PPs were identified by utilizing UHPLC-ESI-HRMS/MS, with the maximum content of cyanidin-3-O-glucoside being 57.01 ± 1.36 mg/g DW. Therefore, this study has positive significance for exploring the potential value of more by-products and obtaining good ecological and economic benefits in the future.

Microwave Treatment vs. Conventional Pasteurization: The Effect on Phytochemical and Microbiological Quality for Citrus-Maqui Beverages

This study uncovered the impacts of microwave (MW) treatments compared to conventional pasteurization (TP) on the quality of functional citrus-maqui beverages, with added sucrose or stevia. The influence of these thermal treatments on the microbiological burden and phytochemical composition was determined by processing under two MW power levels (600 W and 800 W) and TP at 85 °C for 15 s for 60 days at room temperature (20 °C). The results indicated that, beyond the microbiological quality achieved in the juices treated by both MW and TP technology, there were no differences among the treatments regarding the stability of vitamin C, anthocyanin, and flavanone concentrations. However, anthocyanins were more stable in those beverages with sucrose added, rendering a better red color. Besides, all treatments ensured microbiological stability throughout the entire storage time. In conclusion, MW treatment could be considered as an alternative to TP, which ensures microbial safety, protecting functional compounds associated with health effects.

Effects of different food ingredients and additives on the digestibility of extruded and roller-dried maize starch and its application in low glycemic index nutritional formula powder

BACKGROUND

Complex interactions that occur among starch, protein, and fat during food processing affect the taste, texture, and digestibility of starch-based food. The physicochemical properties of starch, in particular its slow digestibility, are greatly influenced by processing techniques such as extrusion and roller-drying. This study investigated the effects of various food ingredients and additives on the digestion properties of maize starch treated with extrusion and roller drying. It designed a nutritional formula to develop low glycemic index products.

RESULTS

The extruded group containing raw maize starch, soybean protein isolate, soybean oil, lecithin and microcrystalline cellulose in the ratio of 580:250:58:20:3 had the best slow digestion properties. Nutritional formulas were designed at the above ratio, with supplements including calcium casein peptide, multi-vitamins, sodium ascorbate, fructooligosaccharides, xylitol, and peanut meal. The sample containing 10% peanut meal and a 1:3 ratio of fructooligosaccharides and xylitol additions obtained the highest sensory evaluation scores. An obvious slow digestion effect was observed in samples produced from the optimal formula.

CONCLUSION

The results of the present study could contribute to the development and production of a low glycemic index, nutritional powder. © 2023 Society of Chemical Industry.

Gastrointestinal digestion assays for evaluating the bioaccessibility of phenolic compounds in fruits and their derivates: an overview

Fruits and their derivatives are sources of phenolic compounds, which contribute to the maintenance of health benefits. In order to exert such properties, these compounds must be exposed to gastrointestinal conditions during digestion. In vitro methods of gastrointestinal digestion have been developed to simulate and evaluate the changes that compounds undergo after being exposed to various conditions. We present, in this review, the major in vitro methods for evaluating the effects of gastrointestinal digestion of phenolic compounds in fruits and their derivatives. We discuss the concept of bioaccessibility, bioactivity, and bioavailability, as well as the conceptual differences and calculations among studies. Finally, the main changes caused by in vitro gastrointestinal digestion in phenolic compounds are also discussed. The significant variation of parameters and concepts observed hinders a better evaluation of the real effects on the antioxidant activity of phenolic compounds, thus, the use of standardized methods in research would contribute for a better understanding of these changes.

Effects of degradation on the physicochemical and antioxidant properties of carboxymethyl pachymaran

Poria cocos (Schw.) Wolf is a well-known edible and medicinal fungus. The polysaccharide in the sclerotium of P. cocos was extracted and prepared into carboxymethyl pachymaran (CMP). Three different degradation treatments including high temperature (HT), high pressure (HP) and gamma irradiation (GI) were used to process CMP. The changes in physicochemical properties and antioxidant activities of CMP were then comparatively investigated. We found that the molecular weights of HT-CMP, HP-CMP, and GI-CMP decreased from 787.9 kDa to 429.8, 569.5 and 6.0 kDa, respectively. Degradation treatments had no effect on the main chains of →3-β-D-Glcp-(1 → while changed the branched sugar residues. The polysaccharide chains of CMP were depolymerized after high pressure and gamma irradiation treatments. The three degradation methods improved the stability of CMP solution while decreased the thermal stability of CMP. In addition, we found that the GI-CMP with lowest molecular weight had the best antioxidant activity. Our results suggest that gamma irradiation treatment could degrade CMP as functional foods with strong antioxidant activity.

Brazil Nut (Bertholletia excelsa) Beverage Processed by High-Pressure Homogenization: Changes in Main Components and Antioxidant Capacity during Cold Storage

High-pressure homogenization (HPH) is an emerging technology for obtaining physical and microbial stability of plant-based milks, but there is little information on the effects of this technology on the phytochemical components of the processed plant food beverage and during its cold storage. The effect of three selected HPH treatments (180 MPa/25 °C, 150 MPa/55 °C, and 50 MPa/75 °C) and pasteurization (PAS) (63 °C, 20 min) on minor lipid constituents, total proteins, phenolic compounds, antioxidant capacity, and essential minerals of Brazil nut beverage (BNB) were studied. Additionally, the study of the possible changes in these constituents was carried out during cold storage at 5 °C for 21 days. The fatty acid profile (dominated by oleic acid and linoleic acid), free fatty acid content, protein, and essential minerals (notable source of Se and Cu) of the processed BNB remained almost stable to treatments (HPH and PAS). Specifically, reductions in squalene (22.7 to 26.4%) and γ-γ-tocopherol (28.4 to 36%) were observed in beverages processed via both non-thermal HPH and thermal PAS, but β-sitosterol remained unchanged. Total phenolics were reduced (24 to 30%) after both treatments, a factor that influenced the observed antioxidant capacity. The studied individual phenolics in BNB were gallic acid, catechin, epicatechin, catechin gallate, and ellagic acid, being the most abundant compounds. During cold storage (5 °C) up to 21 days, changes in the content of phytochemicals, minerals, and total proteins were not noticeable for any treated beverages, and no lipolysis processes were promoted. Therefore, after the application of HPH processing, Brazil nut beverage (BNB) maintained almost unaltered levels of bioactive compounds, essential minerals, total protein, and oxidative stability, remarkable characteristics for its potential development as a functional food.

Effects and impacts of technical processing units on the nutrients and functional components of fruit and vegetable juice

Fruit and vegetable juice (FVJ) has become a favorite beverage for all age groups because of its excellent sensory and nutritional qualities. FVJ has a series of health benefits such as antioxidant, anti-obesity, anti-inflammatory, anti-microbial and anti-cancer. Except for raw materials selection, processing technology and packaging and storage also play a vital role in the nutrition and functional components of FVJ. This review systematically reviews the important research results on the relationship between FVJ processing and its nutrition and function in the past 10 years. Based on the brief elucidation of the nutrition and health benefits of FVJ and the unit operation involved in the production process, the influence of a series of key technology units, including pretreatment, clarification, homogenization, concentration, sterilization, drying, fermentation and packaging and storage, on the nutritional function of FVJ was systematically expounded. This contribution provides an update on the impacts of technical processing units on the nutrients and functional components of FVJ and new perspectives for future studies.

Assessment of the Bioaccessibility of Elaeagnus angustifolia L. Flour and Its Use in Cracker Formulation

In this study, in vitro digestion of polyphenols of oleaster (Elaeagnus angustifolia L.) flour (OF) and the potential use of OF in cracker production were studied. The results showed that 21.90 mg gallic acid equivalent (GAE)/g dry matter (DM) of total polyphenol (TP), 28.15 mg rutin equivalent (RE)/g DM of total flavonoid (TF) and 7709.13 mmol ascorbic acid equivalent (AAE)/100 g DM of antioxidant capacity (AC) were found in OF. The bioaccessibility and content of the OF polyphenols and their AC during in vitro digestion varied depending on the digestion stage. The stability of the OF polyphenols was higher in gastric stage (41.92%) than intestinal one (34.01%). OF was used to replace flour in the cracker formulation at the levels of 5, 10 and 15% (w/w) and increased the TP contents and AC of the crackers compared to the sample without OF (control). The addition of OF to the cracker dough increased the bioaccessibility of the cracker polyphenols. After digestion, bioaccessibilities of enriched crackers (107.90-126.81%) were found higher than that of control sample (93.73%). However, as the level of OF in cracker increased, bioaccessibility of polyphenols decreased. The results generally indicated that oleaster has a good potential for the enrichment of foods.

Application of High-Pressure Homogenization for Apple Juice: An Assessment of Quality Attributes and Polyphenol Bioaccessibility

In the current work, the influence of high-pressure homogenization (HPH) (200, 250, and 300 MPa) on pH, Brix, turbidity, viscosity, particle size distribution (PSD), zeta potential, color, polyphenol oxidase (PPO), peroxidase (POD), polyphenol profile and bioaccessibility of total phenolic compounds was studied. The results show no change in the apple juice's pH, TSS and density. In contrast, other physiochemical properties of apple juice treated with HPH were significantly changed. Besides total phenolic content (15% degradation) in the HPH-treated apple juice at 300 MPa, the PPO and POD activities were reduced by a maximum of 70 and 35%, respectively. Furthermore, among different digestion stages, various values corresponding to PSD and zeta potential were recorded; the total phenolic content was gradually reduced from the mouth to the intestine stage. The polyphenol bioaccessibility of HPH-treated apple juice was 17% higher compared to the untreated apple juice.

Characterization of the flavor, sensory quality and in vitro bioaccessibility in cloudy pomegranate juice treated by high pressure and thermal processing

BACKGROUND

Recently, cloudy pomegranate juice (PJ) has become popular due to its rich phenolic and health-promoting effects. The aim of the present work was to evaluate the application of high hydrostatic pressure processing (HPP), pasteurization (PT) and high-temperature short-time sterilization (HTST) on physicochemical properties (color, flow behavior, turbidity, sugars, organic acids, aroma and sensory evaluation) and in vitro bioaccessibility of total phenolics content (TPC), total flavonoids content (TFC) and phenolics of cloudy PJ.

RESULTS

Compared to HPP, thermal sterilization significantly increased the brightness (L*), redness (a*), total color difference (ΔE) and turbidity, and decreased the TPC and TFC. HPP maintained the volatile profile of cloudy PJ better, while thermal sterilization significantly changed the profile by decreasing alcohols 23.8-32.7% and increasing acids by 33.6%-182.8%. The bioaccessibility of flavonoids, phenolic acids and tannins in the control cloudy PJ after in vitro oral-gastric-intestinal digestion were 1.5%, 4.9%, and 9.0%, respectively, which were not significantly changed by different treatments.

CONCLUSION

These results contributed to promoting the color quality and health benefits of cloudy PJ rich in phenolics by optimizing the processing conditions in the food industry. © 2022 Society of Chemical Industry.

Formulation of Functional Drink with Milk Fortification: Effects on the Bioaccessibility and Intestinal Absorption of Phenolics

Due to a turn toward to functional foods with improved nutritional value, rosehip could be an appropriate candidate to create formulations using a milk matrix. In the present study, the influence of bovine or almond milk fortification on the bioaccessibility and intestinal absorption of rosehip infusion phenolics, mainly catechin, were investigated by a combined method of an in vitro gastrointestinal digestion/Caco-2 cell culture model. The results indicated that bovine (IB) or almond milk (IA) fortification enhanced the retention of total phenolics (TPC; increase of 8.1% and 20.3% for IB and IA, respectively), while there was a decline in the total flavonoids (TFC; decrease of 64% and 17% for IB and IA, respectively) and antioxidant capacity measured by CUPRAC assay (decrease of 15% and 4% for IB and IA, respectively) throughout the gastrointestinal tract in comparison with the control sample (IC). Then, based on the cytotoxicity (SRB) assay, 1/5 times diluted digests were subjected to transepithelial transportation of Caco-2 cells. According to the results, the bovine milk matrix positively affected the transportation of phenolics across the epithelial cell layer. It could be concluded that it is possible to produce functional infusion drinks with improved stability, bioaccessibility, and absorption efficiency of rosehip phenolics in the formulations containing milk matrix.

Effect of geographical location, processing and simulated digestion on antioxidant characteristics of quince (Cydonia oblonga)

Quince fruit (Cydonia oblonga Miller) is an important source of bioactive compounds, especially of phenolic compounds, that's why it is considered a good source of antioxidants. However, it is known that the antioxidant characteristics and the beneficial effect of foods are affected by the variety, geographical origin, processing and gastrointestinal digestion. In this work, the effects of the geographical origin, processing, and simulated digestion of quince jam on its antioxidant characteristics were studied. Phenolic composition and antioxidant capacity were determined in quince fruit and jam from four different locations in San Juan, Argentina. The results showed that quince fruit samples from St. Lucia had the highest total phenolic content (5.13 mg GAE/g; p < 0.05) and in vitro antioxidant capacity measured by ferric-reducing antioxidant power assay (FRAP) and radical-scavenging capacity assay (DPPH· and ABTS·+ ). With regard to quince jam, a positive effect was observed on its antioxidant characteristics after processing. Twenty-one phenolics were detected in jam, being most of them derivatives of hydroxycinnamic acids (eg. 5-caffeoylquinic acid; 4-caffeoylquinic acid and quinic acid). Studies on stability and bioaccessibility of quince phenolics showed that less than 25% of the initial phenolics in jam were detected after digestion being quinic acid and hydroxycinnamic acids the most resistant. The in vitro antioxidant capacity showed, in general, a similar trend to the phenolics content throughout the digestion process. The results obtained showed that the antioxidant activity of quince and jam is related to the type and amount of phenolics in the samples, which depends on the geographical origin, processing, and gastrointestinal digestion. These variables are not always taken into account when studying the probable antioxidant activity of food, even though they should be considered for a complete nutritional evaluation of a food.

Bioaccessibility of Phenolic Compounds and Antioxidant Properties of Goat-Milk Powder Fortified with Grape-Pomace-Seed Extract after In Vitro Gastrointestinal Digestion

This study deals with the evaluation of the bioaccessibility and antioxidant properties of phenolic compounds from heat-treated skim goat-milk powder fortified with grape-pomace-seed extract, after in vitro gastrointestinal digestion. Ultra-high performance liquid chromatography coupled to diode array detection and mass spectrometry (UHPLC-DAD MS/MS) analysis confirmed the abundant presence of phenolic acids and flavan-3-ols in the grape-pomace-seed extract (SE) and heat-treated skim goat-milk/seed-extract powder (TME). After in vitro digestion of TME powder and recovery of total quantified phenolics, flavan-3-ols and phenolic acids were 18.11%, 24.54%, and 1.17%, respectively. Low recovery of grape-pomace-seed phenolics indicated strong milk protein-phenolic interactions. Electrophoretic analysis of a soluble fraction of digested heat-treated skim goat milk (TM) and TME samples showed the absence of bands originating from milk proteins, indicating their hydrolysis during in vitro gastrointestinal digestion. The digested TME sample had better antioxidant properties in comparison to the digested TM sample (except for the ferrous ion-chelating capacity, FCC), due to the presence of bioaccessible phenolics. Taking into account the contribution of the digestive cocktail, digested TME sample had lower values of total phenolic content (TPC), in vitro phosphomolybdenum reducing capacity (TAC) and ferric reducing power (FRP), compared to the undigested TME sample. These results could be attributed to low recovery of phenolic compounds. TME powder could be a good carrier of phenolics to the colon; thus, TME powder could be a promising ingredient in the formulation of functional food.

How to comprehensively improve juice quality: a review of the impacts of sterilization technology on the overall quality of fruit and vegetable juices in 2010-2021, an updated overview and current issues

Fruit and vegetable juices (FVJ) are rich in nutrients, so they easily breed bacteria, which cause microbial pollution and rapid deterioration of their quality and safety. Sterilization is an important operation in FVJ processing. However, regardless of whether thermal sterilization or non-thermal sterilization is used, the effect and its impact on the overall quality of FVJ are strongly dependent on the processing parameters, microbial species, and FVJ matrix. Therefore, for different types of FVJ, an understanding of the impacts that different sterilization technologies have on the overall quality of the juice is important in designing and optimizing technical parameters to produce value-added products. This article provides an overview of the application of thermal and non-thermal technique in the field of FVJ processing over the past 10 years. The operating principle and effects of various technologies on the inactivation of microorganisms and enzymes, nutritional and functional characteristics, physicochemical properties, and sensory quality of a wide range of FVJ are comprehensively discussed. The application of different combinations of hurdle technology in the field of FVJ sterilization processing are also discussed in detail. Additionally, the advantages, limitations, and current application prospects of different sterilization technologies are summarized.

A review of in vitro methods to evaluate the bioaccessibility of phenolic compounds in tropical fruits

International guidelines strongly advise about the frequent and varied intake of plant in diet. In this scenario, the consumption of fruits is closely related to health benefits due to the abundant presence of bioactive substances. Accordingly, the production of tropical fruits has stood out worldwide, reaching records since the past decade. However, to ensure that phenolic substances are indeed used by the body, they need to be accessible for absorption. For this purpose, several methods are used to assess the phenomenon of bioaccessibility. We provide information on i) in vitro methods for the evaluation of the bioaccessibility of phenolic compounds in tropical fruits, including their derivatives and by-products; ii) a study performed using a semi-dynamic in vitro digestion model; iii) simulated digestion with a dialysis membrane step, polyphenol transport/uptake using cell culture, and in vitro colonic fermentation process. Although standardized static and semi-dynamic in vitro digestion methods already exist, few studies use these protocols to assess the bioaccessibility of polyphenols in tropical fruits. To guarantee that in vitro digestion assays reproduce consistent results compared to in vivo reference methods, it is essential to universalize standardized methods that allow the comparison between results, enabling the validation of in vitro digestion methods.

Bioavailability of Rosehip (Rosa canina L.) Infusion Phenolics Prepared by Thermal, Pulsed Electric Field and High Pressure Processing

In this study, the in vitro bioavailability of rosehip infusion phenolics, mainly catechin, as a response to conventional and non-thermal treatments by combining gastrointestinal digestion and a Caco-2 cell culture model, was investigated. After application of thermal treatment (TT, 85 °C/10 min), high pressure (HPP, 600 MPa/5 min) or pulsed electric field (PEF, 15 kJ/kg) processing, all samples were subjected to simulated gastrointestinal digestion. Then, the amount of maximum non-toxic digest ratio was determined by the cytotoxicity sulforhodamine B (SRB) assay. Next, Caco-2 cells were exposed to 1:5 (v/v) times diluted digests in order to simulate the transepithelial transportation of catechin. Results showed that non-thermally processed samples (5.19 and 4.62% for HPP and PEF, respectively) exhibited greater transportation across the epithelial cell layer compared to than that of the TT-treated sample (3.42%). The present study highlighted that HPP and PEF, as non-thermal treatments at optimized conditions for infusions or beverages, can be utilized in order to enhance the nutritional quality of the final products.

Free and Bound Phenolic Profiles of Rosa roxburghii Tratt Leaves and Their Antioxidant and Inhibitory Effects on α-Glucosidase

Rosa roxburghii Tratt (R. roxburghii) tea is a traditional Chinese beverage. This study aims to investigate and compare the phenolics in free and bound forms of two cultivars of R. roxburghii leaves, and their bioactivities. The total phenolic content of free and bound fractions was 72.71 and 17.75 mg GAE/g DW in Gui Nong No. 5 (GNN5) and 94.28 and 11.19 mg GAE/g DW in Seedless Cili (SC). A total of 37 phenolic compounds were characterized and quantified by UPLC-Q-Exactive Orbitrap/MS with ellagic acid, quercitrin, isoquercitrin, and quininic acid in free fraction, while gallic acid, ellagic acid, and hyperoside were main compounds in bound fraction. The free fraction with higher phenolic contents also showed excellent performances on antioxidant activities and α-glucosidase inhibitory potency than bound phenolics. Therefore, the results highlight that R. roxburghii leaves are a promising source enriched in phenolic constituents for functional beverages and nutritional foods.

Effect of high-pressure processing and thermal treatments on color and in vitro bioaccessibility of anthocyanin and antioxidants in cloudy pomegranate juice

In this study, the effect of high-pressure processing (HPP) and thermal treatments, including pasteurization (PT) and high-temperature short-time sterilization (HTST) on pomegranate juice (PJ) color attributes, anthocyanin (ACNs), vitamin C, and in vitro bioaccessibility of ACNs and antioxidants were investigated. Compared to HPP, thermal treatments significantly changed the CIE color, decreased the total monomeric ACNs and total vitamin C contents, and increased the percent polymeric color (PPC) and browning index (BI). Correlation analysis showed that the generation of polymeric ACNs played a significant role in color change during thermal treatments. The recovery of 7 ACNs in the control sample after in vitro gastrointestinal digestion was ranged from 0.43% to 5.0% and total individual ACNs after digestion showed no significant changes among different treatments. These results contributed to promoting the color quality and health benefits of pomegranate juice rich in ACNs by optimizing the processing conditions in the food industry.

Anti-Inflammatory Properties, Bioaccessibility and Intestinal Absorption of Sea Fennel (Crithmum maritimum) Extract Encapsulated in Soy Phosphatidylcholine Liposomes

A sea fennel (Crithmum maritimum) aqueous extract was prepared and loaded into soybean phosphatidylcholine liposomes. Both the free extract (FE), and the empty (L) and loaded (L-FE) liposomes were shown to be non-cytotoxic to THP-1 and Caco-2 cells. The anti-inflammatory effect was tested on THP-1 cells differentiated into macrophages. FE showed anti-inflammatory activity, revealed by the induced secretion of IL-10 cytokines in macrophages that were subsequently stimulated with LPS. Also, a decrease in TNF-α production by L was observed, evidencing that liposomes reduced the pro-inflammatory mediators' secretion. The liposomes (L) showed protective anti-inflammatory activity and also were able to downregulate the inflammation. Furthermore, L-FE were also found to downregulate the inflammation response, as they were able to decrease TNF-α secretion in macrophages previously exposed to LPS. The simulated in vitro gastrointestinal digestion (GID) of FE diminished the chlorogenic acid content (the main polyphenolic compound of the extract) by 40%, while in L-FE, the amount of this phenolic compound increased with respect to the undigested liposomes. The amount of bioaccessible chlorogenic, however, was similar for FE and L-FE. The percentage of chlorogenic acid absorbed through a Caco-2 cell monolayer after 3 h of incubation, was significantly similar for the extract and the liposomes (~1.5%), without finding significant differences once the extract and liposomes were digested.

Bioaccessibility of terebinth (Pistacia terebinthus L.) coffee polyphenols: Influence of milk, sugar and sweetener addition

In this study, terebinth coffee formulations were prepared with whole or skimmed milk with or without sugar/sweetener in order to study the matrix effect on the bioaccessibility of terebinth polyphenols. Quercetin glycosides and catechin were the major flavonoids identified in the terebinth formulations, whereas gallic, protocatechuic, syringic and ellagic acids were determined as the non-flavonoid compounds. The in vitro gastrointestinal digestion model results revealed that addition of whole milk to terebinth coffee increased the total bioaccessible flavonoids significantly (45%) (p < 0.05), whereas skim milk addition did not result in any significant change. Furthermore, antioxidant capacity results measured with CUPRAC assay showed that addition of milk alone or together with sugar/sweetener increases the bioaccessibility of terebinth coffee antioxidants (36-70%) (p < 0.05). Overall, terebinth coffee + whole milk + sugar formulation was found to contain the highest amount of bioaccessible flavonoid and non-flavonoid compounds (42.71-47.07 mg/100 g).

In vitro phenolic bioaccessibility of coffee beverages with milk and soy subjected to thermal treatment and protein-phenolic interactions

The effect of skimmed bovine milk and soy protein on the in vitro bioaccessibility of polyphenols in coffee beverages under thermal treatment (25, 90, and 121 °C) and the protein-phenolic interaction was investigated. Thermal treatment at 90 °C and 121 °C reduced the in vitro bioaccessibility of total and individual phenolic. Skimmed milk and soy protein addition increased the total (by 37.01%-64.21% and 24.74%-47.32%, respectively) and individual phenolic in vitro bioaccessibility (by 4.40%-27.29% and 12.02%-28.61%, respectively) of coffee beverages subjected to thermal treatment at 25, 90 and 121 °C. Compared with soy protein, skimmed milk significantly enhanced the in vitro bioaccessibility of coffee polyphenols, possibly owing to the presence of different types and strengths of noncovalent protein-phenolic interactions. These findings can provide certain theoretical knowledge for optimizing the processing technology and formula of the food industry to help improve the health benefits of milk coffee beverages.

High Hydrostatic Pressure vs. Thermal Pasteurization: The Effect on the Bioactive Compound Profile of a Citrus Maqui Beverage

The effects of high hydrostatic pressure (HHP) compared to thermal pasteurization (TP) were studied in healthy citrus-maqui beverages. The impact of the processing technologies on the microbiological and phytochemical profile was assessed by applying two HHP treatments at 450 and 600 MPa for 180 s and TP at 85 °C for 15 s. The shelf life under refrigeration (4 °C) and room temperature (20 °C) was monitored for 90 days. All treatments ensured microbiological stability at both storage temperatures. Aside from that, the physicochemical parameters were not significantly different after processing or throughout the storage period. Regarding color parameters, an increase in the reddish coloration was observed during storage for those beverages treated by HHP. In general, phenolic compounds were little affected by the processing technique, even when treatment under HHP was more stable than by TP during storage. On the other hand, vitamin C showed great degradation after processing under any condition. It can be concluded that HHP is an effective alternative to thermal treatments, achieving effective microbial inactivation and extending the shelf life of the juices by contributing to a better preservation of color and bioactive compounds.

Ultrasound-homogenization-assisted extraction of polyphenols from coconut mesocarp: Optimization study

Coconut pericarp (shell fiber (mesocarp) and shell (endocarp)), the main by-product of coconut production, is often discarded and causing serious environmental pollution. To make better use of coconut pericarp, the extraction process of polyphenols from coconut mesocarp (CM) carefully studied by screening seven solvent systems, optimizing the assisted ultrasonic process by response surface methodology, and comparing the four processes of Ultrasound-Assisted Extraction (UAE), Homogenization-Assisted Extraction (HAE), Homogenization-Ultrasound-Assisted Extraction (HUAE), and Ultrasound-Homogenization-Assisted Extraction (UHAE). The UAE and HAE are considered to be the main methods for efficient extraction of natural active ingredients. The former effectively destroys the cell wall structure and promotes the intermolecular diffusion based on the cavitation, thermal and mechanical effect of ultrasonic, while the latter breaks the material based on strong shear force between the rotor and stator. Their combinations (HUAE and UHAE) enhance the damage to the cell wall of raw materials and improve the extraction efficiency by the synergistic effect. The results showed that using 60% acetone (V : V) as extraction solvent, solid-liquid ratio of 1:5 g mL^-1, ultrasonic temperature of 80 ℃, ultrasonic time of 80 min, ultrasonic power of 225 W, and then homogenizing at 10,000 rpm for 10 min, the total flavonoid content of CM reached the maximum value of 551.99 ± 12.69 mg Rutin g^-1 dry weight (dw), while the total phenolic content reached the maximum value of 289.48 ± 4.41 mg GAE g^-1 dw at 10,000 rpm for 5 min, which may be related to the oxidative degradation of polyphenols caused by the increase of polyphenol oxidase with the extension of homogenization time. This study provides a technical guarantee for the further utilization of phenolic substances in CM.

Effects of combined application of high-pressure processing and active coatings on phenolic compounds and microbiological and physicochemical quality of apple cubes

BACKGROUND

In recent years the use of high-pressure processing (HPP) of fruit products has steadily increased due to its antimicrobial effectiveness and the retention of nutritional and quality attributes compared to conventional thermal technologies. Edible coatings are already being used to enhance the quality of minimally processed fruits. Thus, apple cubes (AC) and alginate-vanillin-coated apple cubes (AVAC) were subjected to HPP (400 MPa/5 min/35 °C). The microbiological and physicochemical parameters were evaluated and the bioactive compounds were monitored before and after HPP of apple cubes. Also, an in vitro gastrointestinal digestion (GID) was conducted.

RESULTS

HPP left L. monocytogenes counts below the detection limit (2 log UFC g^-1 ), regardless of the presence of coating. For E. coli, HPP + active coating showed a synergism affording the greatest reduction (>5 log) for AVAC-HPP. Firmness was maintained in AVAC-HPP samples, while AC-HPP samples suffered reductions of 35%. Colour attributes were also better retained in AVAC-HPP samples. In general, HPP led to a decrease in phenolic compounds. Regarding the effects of GID, vanillin-based active coating exerted a protective effect on some phenolics. Thus, p-coumaroylquinic acid concentration was maintained for AVAC and AVAC-HPP during GID. Epigallocatechin, the compound with the highest concentration in apple cubes, increased for AVAC (106%) and AVAC-HPP (57%). Also, phloridzin concentration increased for AVAC-HPP (17%). At the end of GID, procyanidin B1 and epigallocatechin were the main phenolic compounds for all samples, AVAC showing the highest concentration.

CONCLUSIONS

This work demonstrates that the combined application of HPP and active coatings on apple cubes could be used to obtain a safe and good-quality product. © 2021 Society of Chemical Industry.

Recent Advances toward the Application of Non-Thermal Technologies in Food Processing: An Insight on the Bioaccessibility of Health-Related Constituents in Plant-Based Products

Fruits and vegetables are rich sources of bioactive compounds and micronutrients. Some of the most abundant are phenols and carotenoids, whose consumption contributes to preventing the occurrence of degenerative diseases. Recent research has shown the potential of non-thermal processing technologies, especially pulsed electric fields (PEF), ultrasounds (US), and high pressure processing (HPP), to trigger the accumulation of bioactive compounds through the induction of a plant stress response. Furthermore, these technologies together with high pressure homogenization (HPH) also cause microstructural changes in both vegetable tissues and plant-based beverages. These modifications could enhance carotenoids, phenolic compounds, vitamins and minerals extractability, and/or bioaccessibility, which is essential to exert their positive effects on health. Nevertheless, information explaining bioaccessibility changes after non-thermal technologies is limited. Therefore, further research on food processing strategies using non-thermal technologies offers prospects to develop plant-based products with enhanced bioaccessibility of their bioactive compounds and micronutrients. In this review, we attempt to provide updated information regarding the main effects of PEF, HPP, HPH, and US on health-related compounds bioaccessibility from different vegetable matrices and the causes underlying these changes. Additionally, we propose future research on the relationship between the bioaccessibility of bioactive compounds and micronutrients, matrix structure, and non-thermal processing.

Skimmed Goat's Milk Powder Enriched with Grape Pomace Seed Extract: Phenolics and Protein Characterization and Antioxidant Properties

The aim of this research was phenolics and protein characterization and antioxidant properties evaluation of skimmed thermally treated goat's milk powder enriched with different concentration of grape pomace seed extract (SE). The dominant phenolics in SE were phenolic acids, flavan-3-ols and procyanidins. Different electrophoretic techniques together with UHPLC-MS/MS analysis revealed the presence of phenolics-protein interactions in the samples, mainly procyanidins with whey protein/caseins complexes. Addition of SE into thermally treated goat's milk significantly improved antioxidant properties of goat's milk such as TAC, FRP, DPPH^• and ABTS^•+ scavenging activity. Gallic acid, catechin, and procyanidins mostly contributed to these activities. The schematic representation of phenolics-casein micelles interactions in thermally treated goat's milk enriched with SE was given. The addition of SE into thermally treated goat's milk can be a promising strategy in food waste recovery and to enhance the beneficial health effects of goat's milk-based functional foods.

Pulsed electric field treatment strategies to increase bioaccessibility of phenolic and carotenoid compounds in oil-added carrot purees

The impact of pulsed electric fields (PEF) and their combination with a thermal treatment on the bioaccessibility of phenolic and carotenoid compounds in oil-added carrot puree (5 %) was investigated. Fractions of such puree were differently treated: subjected to PEF (5 pulses of 3.5 kV cm^-1) (PEF); thermally treated (70 °C for 10 min) (T) or first PEF treated and then thermally treated (PEF/T). Purees were in vitro digested, carotenoid and phenolic content and bioaccessibility were determined. Likewise, quality attributes and microstructure were analyzed. Generally, treatments did not affect carotenoid content and quality attributes, whereas phenolic content dramatically decreased after PEF. Nevertheless, all treatments enhanced both compounds bioaccessibilities, which were trebled in PEF-treated purees. Particle size reduction may suggest that microstructural changes could be responsible of bioaccessibility increases. Therefore, PEF could be a feasible treatment to enhance phenolic and carotenoid bioaccessibility without altering quality attributes of carrot-based puree.

Applying Pulsed Electric Fields to Whole Carrots Enhances the Bioaccessibility of Carotenoid and Phenolic Compounds in Derived Products

We propose the application of pulsed electric fields (PEF) to carrots to obtain derived products with increased phenolic and carotenoid bioaccessibility. For this purpose, juices, purees, and oil-added purees were obtained from whole PEF-treated carrots (five pulses of 3.5 kV cm-1; 0.61 kJ kg-1). In order to obtain shelf-stable products, the effect of a thermal treatment (70 °C for 10 min) was also studied. Carrot juices exhibited the highest carotenoid (43.4 mg/100 g fresh weight) and phenolic (322 mg kg-1 dry weight) contents. However, caffeic and coumaric acid derivatives were highly sensitive to PEF. The phenolic bioaccessibility reached 100% in purees obtained from the PEF-treated carrots, whereas the further thermally treated oil-added purees exhibited the greatest carotenoid bioaccessibility (7.8%). The increase in carotenoid bioaccessibility could be related to their better release and solubilization into micelles. The results suggest that food matrix aspects apart from particle size (e.g., pectin characteristics) are involved in phenolic bioaccessibility.

Effect of in vitro digestion on chestnut outer-skin and inner-skin bioaccessibility: The relationship between biotransformation and antioxidant activity of polyphenols by metabolomics

Chestnut skin is rich in polyphenols that have been linked to health for their antioxidant activity. However, chestnut outer-skin extract (COE), chestnut inner-skin extract (CIE), and their digested products have different compositions of polyphenols, and therefore their antioxidant activities might differ as well. Here, we study the effect of in vitro digestion on their total phenol content, antioxidant capacity, and individual phenolic profile to clarify the relationship between biotransformation and antioxidant activity. Compared to undigested samples, total phenol content and antioxidant activity of digested chestnut outer-skin extract (DCOE) and digested chestnut inner-skin extract (DCIE) had significantly higher values. The changes of phenolic composition and antioxidant activity after digestion were mainly due to the anthocyanin biosynthesis involving glycosylation, acylation, methoxylation and their reverse processes. All these data suggest that as chestnut processing by-products, COE and CIE are raw material sources of antioxidant-rich active substances and need more sufficient utilization.

Effect of Adding Resistant Maltodextrin to Pasteurized Orange Juice on Bioactive Compounds and Their Bioaccessibility

Resistant maltodextrin (RMD) is a water-soluble and fermentable functional fiber. RMD is a satiating prebiotic, reducer of glucose and triglycerides in the blood, and promoter of good gut health, and its addition to food is increasingly frequent. Therefore, it is necessary to study its potential effects on intrinsic bioactive compounds of food and their bioaccessibility. The aim of this study was to evaluate the effect of adding RMD on the bioactive compounds of pasteurized orange juice with and without pulp, and the bioaccessibility of such compounds. RMD was added at different concentrations: 0 (control sample), 2.5%, 5%, and 7.5%. Ascorbic acid (AA) and vitamin C were analyzed using HPLC, whereas total phenols, total carotenoids (TC), and antioxidant capacity were measured using spectrophotometry. After that, sample in vitro digestibility was assessed using the standardized static in vitro digestion method. The control orange juice with pulp presented significantly higher values of bioactive compounds and antioxidant capacity than the control orange juice without pulp (p < 0.05). RMD addition before the juice pasteurization process significantly protected all bioactive compounds, namely total phenols, TC, AA, and vitamin C, as well as the antioxidant capacity (AC) (p < 0.05). Moreover, this bioactive compound protective effect was higher when higher RMD concentrations were added. However, RMD addition improved phenols and vitamin C bioaccessibility but decreased TC and AA bioaccessibility. Therefore, the AC value of samples after gastrointestinal digestion was slightly decreased by RMD addition. Moreover, orange pulp presence decreased total phenols and TC bioaccessibility but increased AA and vitamin C bioaccessibility.

Dietary Plant Polyphenols: Effects of Food Processing on Their Content and Bioavailability

Dietary plant polyphenols are natural bioactive compounds that are increasingly attracting the attention of food scientists and nutritionists because of their nutraceutical properties. In fact, many studies have shown that polyphenol-rich diets have protective effects against most chronic diseases. However, these health benefits are strongly related to both polyphenol content and bioavailability, which in turn depend on their origin, food matrix, processing, digestion, and cellular metabolism. Although most fruits and vegetables are valuable sources of polyphenols, they are not usually consumed raw. Instead, they go through some processing steps, either industrially or domestically (e.g., cooling, heating, drying, fermentation, etc.), that affect their content, bioaccessibility, and bioavailability. This review summarizes the status of knowledge on the possible (positive or negative) effects of commonly used food-processing techniques on phenolic compound content and bioavailability in fruits and vegetables. These effects depend on the plant type and applied processing parameters (type, duration, media, and intensity). This review attempts to shed light on the importance of more comprehensive dietary guidelines that consider the recommendations of processing parameters to take full advantage of phenolic compounds toward healthier foods.

Effects of processing parameters on furan formation in canned strawberry jam

The formation mechanism of furan has been studied extensively in model systems, however, furan formation in real foods are complex and far from being fully understood. In this study, the effects of acid-regulating agent (citric acid), sugar addition (glucose, fructose and sucrose) and thickening agents (xanthan gum, κ-carrageenan and pectin) on furan levels in strawberry jams were studied; meanwhile the formation pathway of furan in canned strawberry jam was proposed by carbon module labeling (CAMOLA) technique. Our results suggested low pH promoted furan formation in strawberry jam. Besides, fructose produces more furans than sucrose and glucose, and the addition of xanthan gum reduced furan levels significantly. The kinetic data showed that ascorbic and dehydroascorbic acid degradation followed first-order kinetics while rate of furan formation followed zero-order kinetics. This study presented the possibility of mitigating furan formation in canned strawberry jams by optimization of processing parameters and addition of xanthan gum.