High pressure homogenization increases the in vitro bioaccessibility of α- and β-carotene in carrot emulsions but not of lycopene in tomato emulsions

Beta-carotene and its protective effect on gastric cancer

Beta-carotene is an important natural pigment that is very beneficial to human health. It is widely found in vegetables and fruits. The three main functions are antioxidant effects, cell gap junction-related functions and immune-related functions. Because of its diverse functions, beta-carotene is believed to prevent and treat many chronic diseases. Gastric cancer is one of the most important diseases it can treat. Gastric cancer is a type of cancer with a high incidence. Its etiology varies, and the pathogenesis is complex. Gastric cancer seriously affects human health. The role of beta-carotene, a natural nutrient, in gastric cancer has been explored by many researchers, including molecular mechanisms and epidemiological studies. Molecular studies have mainly focused on oxidative stress, cell cycle, signal transduction pathways and immune-related mechanisms of beta-carotene in gastric cancer. Many epidemiological surveys and cohort studies of patients with gastric cancer have been conducted, and the results of these epidemiological studies vary due to the use of different research methods and analysis of different regions. This paper will summarize the results of these studies, mainly in terms of molecular mechanisms and epidemiological research results, which will provide a systematic basis for future studies of the treatment and prognosis of gastric cancer. This paper will help researchers identify new research directions.

Effect of pulsed electric fields on carotenoid and phenolic bioaccessibility and their relationship with carrot structure

Phenolic compounds (PC) and carotenoids from carrots are bound to dietary fibre or stored in vacuoles and chromoplasts, respectively. To exert their antioxidant effects these compounds must be released during digestion, which is hindered by such barriers. Pulsed electric fields (PEF) modify cell membrane permeability, thus enhancing their bioaccessibility. The effect of PEF on the carrot carotenoid and PC content and bioaccessibility was investigated. With this purpose, PEF-treated carrots (5 pulses of 3.5 kV cm^-1) were stored for 24 h at 4 °C and microstructure was evaluated before subjecting them to in vitro digestion. PEF did not affect carotenoid content, whereas their bioaccessibility improved (11.9%). Likewise, PEF increased the content of some PC, e.g. coumaric acid (163.2%), probably caused by their better extractability. Conversely, caffeic acid derivatives decreased, which may be associated to greater contact with oxidative enzymes. Total PC bioaccessibility (20.8%) and some derivatives increased, e.g. caffeoylshikimic (68.9%), whereas some decreased (e.g. ferulic acid). Structural changes caused by PEF may improve bioaccessibility of carotenoids and PC by favouring their release and easy access to digestive enzymes. However, other antioxidants may be further degraded or entrapped during digestion. Therefore, PEF is an effective technology for obtaining carrots with enhanced carotenoids and phenolic bioaccessibility.

Impact of Innovative Technologies on the Content of Vitamin C and Its Bioavailability from Processed Fruit and Vegetable Products

Nowadays, thermal treatments are used for extending the shelf-life of vegetable and fruit products by inactivating microorganisms and enzymes. On the other hand, heat treatments often induce undesirable changes in the quality of the final product, e.g., losses of nutrients, color alterations, changes in flavor, and smell. Therefore, the food industry is opening up to new technologies that are less aggressive than thermal treatment to avoid the negative effects of thermal pasteurization. Non-thermal processing technologies have been developed during the last decades as an alternative to thermal food preservation. Processing changes the structure of fruit and vegetables, and hence the bioavailability of the nutrients contained in them. In this review, special attention has been devoted to the effects of modern technologies of fruit and vegetable processing, such as minimal processing (MPFV), high-pressure processing (HPP), high-pressure homogenization (HPH), ultrasounds (US), pulsed electric fields (PEF), on the stability and bioavailability of vitamin C.

Evaluation of processing methods and oral mastication on the carotenoid bioaccessibility of restructured carrot chips

BACKGROUND

Carrot carotenoids are typically located in chromoplasts, forming a crystalline substructure. Cell walls and chromoplasts therefore constitute two major physical barriers to the release of carotenoids from the food matrix during digestion. The release of carotenoids from these physical barriers is supposed to be substantially affected by mechanical factors during food processing and oral mastication. Given the implications of this, the effects of four different processing procedures, and various mastication levels, on the carotenoid bioaccessibility of carrot chips were evaluated.

RESULTS

Restructuring and drying methods substantially affected the carotenoid bioaccessibility of carrot chips. The highest carotenoid bioaccessibility was obtained for the air-dried combined with instant pressure-drop-dried (AD-DIC) restructured chips. Although the fresh carrots possessed the highest carotenoid content, their bioaccessibility was lower than that of the carrot chips. The evolution of the particle sizes of the samples was responsible for the changes in carotenoid bioaccessibility due to oral masitication. The particle size of the fresh carrots decreased with increasing oral masitication, which favored carotenoid bioaccessibilty. However, the restructured chips that combined freeze drying with instant pressure-drop drying (R-FD-DIC) demonstrated the opposite trend, probably caused by the severe aggregation of the sample during digestion, which compromised the effect of mastication on the release of carotenoid.

CONCLUSION

Data regarding the effects of the drying process and oral mastication digestion behavior on the samples suggested that AD-DIC-dried restructured carrot chips are effective in enhancing carotenoid bioaccessibility, which explains the key factors involved in the release of carotenoids from carrot chips prepared by different processes. © 2020 Society of Chemical Industry.

Dietary β-Cryptoxanthin and α-Carotene Have Greater Apparent Bioavailability Than β-Carotene in Subjects from Countries with Different Dietary Patterns

β-carotene, α-carotene and β-cryptoxanthin are greater contributors to vitamin A intake than retinol in the human diet for most people around the world. Their contribution depends on several factors, including bioavailability and capacity of conversion into retinol. There is an increasing body of research showing that the use of retinol activity equivalents or retinol equivalents could lead to the underestimation of the contribution of β-cryptoxanthin and of α-carotene. The aim is to assess their apparent bioavailability by comparing concentrations in blood to their dietary intakes and identifying the major food contributors to their dietary intake. Dietary intake (3-day 24-h records) and serum concentrations (by HPLC) were calculated in normolipemic subjects with adequate retinol status (≥1.1 µmol/L) from our studies (n = 633) and apparent bioavailability calculated from 22 other studies (n = 29,700). Apparent bioavailability was calculated as the ratio of concentration in the blood to carotenoid intake. Apparent bioavailabilities for α-carotene and β-cryptoxanthin were compared to those for β-carotene. Eating comparable amounts of α-carotene, β-cryptoxanthin and β-carotene foods resulted in 55% greater α-carotene (95% CI 35, 90) and 686% higher β-cryptoxanthin (95% CI 556, 1016) concentrations than β-carotene in blood. This suggests differences in the apparent bioavailability of α-carotene and β-cryptoxanthin and even larger differences with β-cryptoxanthin, greater than that of β-carotene. Four fruits (tomato, orange, tangerine, red pepper) and two vegetables (carrot, spinach) are the main contributors to their dietary intake (>50%) in Europeans.

Impacts of thermal and non-thermal processing on structure and functionality of pectin in fruit- and vegetable- based products: A review

Pectin, a major polysaccharide found in the cell walls of higher plants, plays major roles in determining the physical and nutritional properties of fruit- and vegetable-based products. An in-depth understanding of the effects of processing operations on pectin structure and functionality is critical for designing better products. This review, therefore, focuses on the progress made in understanding the effects of processing on pectin structure, further on pectin functionality, consequently on product properties. The effects of processing on pectin structure are highly dependent on the processing conditions. Targeted control of pectin structure by applying various processing operations could enhance textural, rheological, nutritional properties and cloud stability of products. While it seems that optimizing product quality in terms of physical properties is counteracted by optimizing the nutritional properties. Therefore, understanding plant component biosynthesis mechanisms and processing mechanisms could be a major challenge to balance among the quality indicators of processed products.

Nutraceutical nanodelivery; an insight into the bioaccessibility/bioavailability of different bioactive compounds loaded within nanocarriers

Nanofoods is a current concept that is based on the application of nanotechnologies in the preparation of safe foods, with superior nutritional and sensory characteristics, and capable of providing multiple health benefits. In line with the principles of this concept, food scientists have focused on developing new types of nano biosystems that can contribute to increasing the bioavailability of bioactive compounds used in food fortification. Numerous research teams have investigated the main factors limiting oral bioavailability including: bioaccessibility, absorption and transformation of bioactive compounds and bioactive-loaded nanocarriers. The physicochemical processes involved in the factors limiting oral bioavailability have been extensively studied, such asthe release, solubility and interaction of bioactive compounds and nanocarriers during food digestion, transport mechanisms of bioactive compounds and nanoparticles through intestinal epithelial cells as well as the chemical and biochemical transformations in phase I and phase II reactions. In this comprehensive review, the physicochemical processes involved in the bioaccessibility/bioavailability of different encapsulated bioactive compounds, that play an important role in human health, will be explained including polyphenols, phytosterols, carotenoids, vitamins and minerals. In particular, the mechanisms involved in the cellular uptake of bioactive-loaded nanocarriers including transcellular transport (diffusion, endocytosis, pinocytosis, transcytosis, phagocytosis), paracellular transport (through the "tight junctions" between epithelial cells), and the active transport of bioactive compounds under the action of membrane transporters are highlighted.

Influence of high pressure homogenization and pasteurization on the in vitro bioaccessibility of carotenoids and flavonoids in orange juice

Production of high-quality healthy foods through sustainable methodologies is an urgent necessity. High pressure homogenization (HPH) is an interesting alternative to obtain premium citrus juices, but its effects on bioactive compounds are unclear. There was studied the influence of HPH (150 MPa) and pasteurization (92 °C for 30 s and 85 °C for 15 s) processing on physicochemical properties and in vitro bioaccessibility of carotenoids and flavonoids in orange juices. Regarding fresh juice, physicochemical properties of samples remained unchanged although cloudiness was improved by homogenization. Pasteurization did not affect total carotenoids content and retinol activity equivalents (RAE) of juices whereas homogenization yielded a significant reduction (1.37 and 1.35-fold, respectively). Interestingly, particle size reduction from homogenization drastically enhanced (about 5-fold) bioaccessibility of carotenoids including hardly bioaccessible epoxycarotenoids, finding unaltered rates in pasteurized samples. Bioaccessibility of flavonoids was constant in all cases. Results can promote HPH as an efficient option to obtain health-enhanced foods.

Oxidative stability of extra-virgin olive oil enriched or not with lycopene. Importance of the initial quality of the oil for its performance during in vitro gastrointestinal digestion

The performance of commercial non-enriched and lycopene-enriched extra-virgin olive oils (EVOO) during in vitro gastrointestinal digestion was studied in order to elucidate potential benefits of lycopene addition. Samples were analyzed before and after digestion by Proton Nuclear Magnetic Resonance (¹H NMR) and Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). EVOO samples differed in both main (oleic and linoleic acyl groups) and minor components (phenolic and oxidation compounds). Regardless of the presence of lycopene, all the samples reached a high degree of lipolysis and showed high stability towards oxidation under digestion conditions. Rather than oxidation reactions, the hydroperoxides initially present in the oil were reduced to more stable hydroxides. Likewise, hydroxy-diene isomerization from cis,trans to trans,trans occurred. Hence, the presumed antioxidant effect of lycopene was not noticed during in vitro digestion of EVOO. Similar experiments carried out with a more polyunsaturated oil (sunflower oil) indicated that lycopene slowed down the advance of oxidation slightly. However, in the case of EVOO, its initial quality prevailed over the slight antioxidant effect exerted by lycopene at the concentration present in commercial samples, determining the oxidation compound profile of the digests.

Effects of high pressure homogenization and addition of oil on the carotenoid bioaccessibility of carrot juice

High pressure homogenization combined with the addition of oil or emulsion had the potential to boost the carotenoid bioaccessibility.

Application of pulsed electric fields to tomato fruit for enhancing the bioaccessibility of carotenoids in derived products

The application of pulsed electric fields (PEFs) to whole tomatoes is proposed as a pre-processing treatment to obtain purees with high health-related properties. Tomato fruit was subjected to different electric field strengths (0.4, 1.2 and 2 kV cm-1) and number of pulses (5, 18 and 30 pulses). Tomatoes were stored at 4 °C for 24 h after PEF processing and then ground and mixed with 5% olive oil. The resulting tomato-based product was subjected to in vitro gastrointestinal digestion. PEF treatments significantly increased the amount and bioaccessible fraction of carotenoids in the derived product. Treatments conducted at 2 kV cm-1 and 30 pulses led to the greatest increase in the concentration of any of the carotenoids studied in tomato-based products. The amount of carotenoids incorporated into the micellar phase was increased in the products obtained from PEF-treated tomatoes, especially after the application of 5 pulses at 2 kV cm-1. Under such treatment conditions, the bioaccessibility of lycopene, δ-carotene, β-carotene, γ-carotene and lutein was increased by 132%, 2%, 53%, 527% and 125%, respectively. Therefore, the application of PEFs as a pre-treatment could be considered as a promising technology to obtain tomato derivatives with high antioxidant potential.

Supercritical Fluid Extraction of Berry Seeds: Chemical Composition and Antioxidant Activity

The influence of supercritical fluid extraction (SFE) and solvent extraction of oils from cloudberry, bilberry, and black currant seeds on the yield, chemical properties, and recovery of antioxidant compounds was investigated. SFE was performed for 1 h at 350 bar and at 50°C and 80°C. Fatty acids, vitamin E, carotenoids, and free radical-scavenging activity (DPPH) were assayed. SFE at 80°C resulted in higher oil yields for cloudberry and black currant seeds. The oils were rich in polyunsaturated fatty acids (PUFAs) (66.8%–75.9% w/w), with high percentages of linoleic and α-linolenic acids. The black currant seed extracts had the highest concentrations of vitamin E (range, 113.0–241.8 mg/100 g oil) and carotenoids (range, 11.5–32.3 mg/100 g oil) and the highest antioxidant activity. The cloudberry seed oils also had high antioxidant content and activity. These findings indicate the potential of SFE for the recovery of PUFA and antioxidant compounds in berry by-products.

In Vitro Bioaccessibility of Colored Carotenoids in Tomato Derivatives as Affected by Ripeness Stage and the Addition of Different Types of Oil

The simultaneous effect of tomato ripeness stage (mature green, pink, and red-ripe), mechanical processing (dicing and grinding), and oil addition (coconut, sunflower, and olive oils) on the amount and bioaccessible fraction of carotenoids were evaluated. Tomato products obtained from fruits at the most advanced ripeness stage exhibited the greatest values of both concentration and bioaccessible fraction of total carotenoids and lycopene. The type of processing also exerted an important influence on carotenoids content, as well as on its bioaccessibility. Thus, despite the concentration of carotenoids in tomato puree significantly decreased (36% to 59%), their bioaccessibility was greater (up to 2.54-fold increase) than in tomato cubes. Moreover, the addition of oil significantly improved the carotenoid bioaccessibility, especially when olive oil was added, reaching up to 21-fold increase with respect to samples without oil. The results obtained clearly indicate that carotenoids bioaccessibility of tomato derivatives was strongly influenced by the ripeness stage of the fruit, processing and the addition of oil.

PRACTICAL APPLICATION

Bioaccessibility of carotenoids is known to be affected by different factors. This study provides useful information about the synergic effect of different factors affecting the amount and the bioaccessible fraction of carotenoids, especially lycopene, in two common tomato derivatives. The findings of this work may contribute to develop tomato derivatives with high content of bioaccessible carotenoids, leading to the enhancement of their health-promoting properties.

Effect of the Composition and Structure of Excipient Emulsion on the Bioaccessibility of Pesticide Residue in Agricultural Products

The influence of co-ingestion of food emulsions with tomatoes on the bioaccessibility of a model pesticide (chlorpyrifos) was studied. Emulsions were fabricated with different oil contents (0-8%), lipid compositions (medium chain triglyceride (MCT) and corn oil), and particle diameters (d₃₂ = 0.17 and 10 μm). The emulsions were then mixed with chlorpyrifos-contaminated tomato puree, and the mixtures were subjected to a simulated gastrointestinal tract (GIT) consisting of mouth, stomach, and small intestine. The particle size, surface charge, and microstructure of the emulsions was measured as they passed through the GIT, and chlorpyrifos bioaccessibility was determined after digestion. The composition and structure of the emulsions had a significant impact on chlorpyrifos bioaccessibility. Bioaccessibility increased with increasing oil content and was higher for corn oil than MCT, but did not strongly depend on oil droplet size. These results suggest that co-ingestion of emulsions with fruits or vegetables could increase pesticide bioaccessibility.

Role of structural barriers in the in vitro bioaccessibility of anthocyanins in comparison with carotenoids

Although natural structural barriers are factors limiting nutrient bioaccessibility, their specific role in anthocyanin bioaccessibility is still unknown. To better understand how natural barriers govern bioactive compound bioaccessibility, an experimental approach comparing anthocyanins and carotenoids was designed, using a single plant matrix. Initial results revealed increased anthocyanin bioaccessibility in masticated black carrot. To explain this observation, samples with increasing levels of bioencapsulation (free-compound, homogenized-puree, puree) were examined. While carotenoid bioaccessibility was inversely proportional to the level of bioencapsulation, barrier disruption did not increase anthocyanin bioaccessibility. This means that mechanical processing is of particular importance in the case of carotenoid bioaccessibility. While micelle incorporation is the limiting factor for carotenoid bioaccessibility, anthocyanin degradation under alkaline conditions in the gastrointestinal tract dominates. In the absence of structural barriers, anthocyanin bioaccessibility is greater than that of carotenoids.

Bioaccessibility of provitamin A carotenoids from fruits: application of a standardised static in vitro digestion method

Provitamin A carotenoids (β-carotene, α-carotene, and β-cryptoxanthin) contribute to the dietary intake of vitamin A and are associated with decreased risk of many chronic diseases. Besides their contents in foods, their bioaccessibility is of great interest since it represents the amount that will be absorbed in the gut. The aim of this study was to adopt, for the first time, the in vitro digestion model suitable for food, proposed in a consensus paper by Minekus et al. (2014), to assess the bioaccessibility of carotenoids from the fruits that are the major contributors to the intake of β-cryptoxanthin in Spain (orange, tangerine, red pepper, peach, watermelon, and persimmon) and loquat. The highest β-cryptoxanthin content and the lowest bioaccessibility was found in mandarin and loquat (13331.6 and 929.2 μg per 100 g respectively), whereas the highest contents of β-carotene and α-carotene were recorded in red pepper (1135.3 and 90.4 μg per 100 g respectively). The bioaccessibility of β-cryptoxanthin was similar to that of β-carotene (0.02-9.8% and 1-9.1%, respectively) and was higher than that of β-carotene in red pepper, watermelon and peach. α-Carotene bioaccessibility ranged between 0% and 4.6%. We discuss the critical factors for comparing our data: the form of the food being analyzed (raw/cooked/previously frozen, in the presence or absence of oil/fat) and the protocol for bioaccessibility assessment. Different food processing techniques may increase carotenoid bioaccessibility compared to raw food. However, given the difficulties encountered when comparing the results of studies on bioaccessibility, it seems logical to propose the application of the previously mentioned standardized in vitro protocol.

Natural Phyto-Bioactive Compounds for the Treatment of Type 2 Diabetes: Inflammation as a Target

Diabetes is a metabolic, endocrine disorder which is characterized by hyperglycemia and glucose intolerance due to insulin resistance. Extensive research has confirmed that inflammation is closely involved in the pathogenesis of diabetes and its complications. Patients with diabetes display typical features of an inflammatory process characterized by the presence of cytokines, immune cell infiltration, impaired function and tissue destruction. Numerous anti-diabetic drugs are often prescribed to diabetic patients, to reduce the risk of diabetes through modulation of inflammation. However, those anti-diabetic drugs are often not successful as a result of side effects; therefore, researchers are searching for efficient natural therapeutic targets with less or no side effects. Natural products' derived bioactive molecules have been proven to improve insulin resistance and associated complications through suppression of inflammatory signaling pathways. In this review article, we described the extraction, isolation and identification of bioactive compounds and its molecular mechanisms in the prevention of diabetes associated complications.

Enzymatic cell wall degradation of high-pressure-homogenized tomato puree and its effect on lycopene bioaccessibility

BACKGROUND

High-pressure homogenization disrupts cell structures, assisting carotenoid release from the matrix and subsequent micellarization. However, lycopene bioaccessibility of tomato puree upon high-pressure homogenization is limited by the formation of a process-induced barrier. In this context, cell wall-degrading enzymes were applied to hydrolyze the formed barrier and enhance lycopene bioaccessibility.

RESULTS

The effectiveness of the enzymes in degrading their corresponding substrates was evaluated (consistency, amount of reducing sugars, molar mass distribution and immunolabeling). An in vitro digestion procedure was applied to evaluate the effect of the enzymatic treatments on lycopene bioaccessibility. Enzymatic treatments with pectinases and cellulase were proved to effectively degrade their corresponding cell wall polymers; however, no further significant increase in lycopene bioaccessibility was obtained.

CONCLUSION

A process-induced barrier consisting of cell wall material is not the only factor governing lycopene bioaccessibility upon high-pressure homogenization.

Role of structural barriers for carotenoid bioaccessibility upon high pressure homogenization

A specific approach to investigate the effect of high pressure homogenization on the carotenoid bioaccessibility in tomato-based products was developed. Six different tomato-based model systems were reconstituted in order to target the specific role of the natural structural barriers (chromoplast substructure/cell wall) and of the phases (soluble/insoluble) in determining the carotenoid bioaccessibility and viscosity changes upon high pressure homogenization. Results indicated that in the absence of natural structural barriers (carotenoid enriched oil), the soluble and insoluble phases determined the carotenoid bioaccessibility upon processing whereas, in their presence, these barriers governed the bioaccessibility. Furthermore, it was shown that the increment of the viscosity upon high pressure homogenization is determined by the presence of insoluble phase, however, this result was related to the initial ratio of the soluble:insoluble phases in the system. In addition, no relationship between the changes in viscosity and carotenoid bioaccessibility upon high pressure homogenization was found.

Mind the gap-deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites--a position paper focusing on carotenoids and polyphenols

Various secondary plant metabolites or phytochemicals, including polyphenols and carotenoids, have been associated with a variety of health benefits, such as reduced incidence of type 2 diabetes, cardiovascular diseases, and several types of cancer, most likely due to their involvement in ameliorating inflammation and oxidative stress. However, discrepancies exist between their putative effects when comparing observational and intervention studies, especially when using pure compounds. These discrepancies may in part be explained by differences in intake levels and their bioavailability. Prior to exerting their bioactivity, these compounds must be made bioavailable, and considerable differences may arise due to their matrix release, changes during digestion, uptake, metabolism, and biodistribution, even before considering dose- and host-related factors. Though many insights have been gained on factors affecting secondary plant metabolite bioavailability, many gaps still exist in our knowledge. In this position paper, we highlight several major gaps in our understanding of phytochemical bioavailability, including effects of food processing, changes during digestion, involvement of cellular transporters in influx/efflux through the gastrointestinal epithelium, changes during colonic fermentation, and their phase I and phase II metabolism following absorption.

Home processing of tomatoes (Solanum lycopersicum): effects on in vitro bioaccessibility of total lycopene, phenolics, flavonoids, and antioxidant capacity

BACKGROUND

In order to investigate the effect of home processing on the bioaccessibility of health-related constituents of tomatoes, total lycopene, phenolics, flavonoids and antioxidant capacity were determined from seven different tomato products using an in vitro gastrointestinal digestion model. Additionally, the changes in the contents of the major tomato phenolics were determined and compared for these different tomato products using HPLC.

RESULTS

The results revealed that paste processing and drying significantly increased the bioaccessible total lycopene content (2.2- and 3.8-fold, respectively), total phenolic content (2.3- and 2.0-fold, respectively), total flavonoid content (9.0- and 2.5-fold, respectively) and total antioxidant capacity (6.3- and 8.0-fold for the DPPH assay, 26- and 33-fold for the CUPRAC assay, respectively) (P < 0.05) compared to fresh tomatoes. HPLC analysis revealed significantly lower (P < 0.05) rutin content in puree and juice. The loss of naringenin chalcone in some tomato products, as well as its conversion into naringenin in heat-treated products was observed.

CONCLUSION

The current study provided valuable insights into the changes in the content and bioaccessibility of tomato antioxidants as a result of home processing.