Carotenoid Bioaccessibility Research Articles

Insights on the Bioaccessibility of Natural Pigments from Diatom Chaetoceros calcitrans.

This study aimed to investigate the bioaccessibility of carotenoids and chlorophylls from the biomass of microalgae Chaetoceros calcitrans. The samples were submitted to an in vitro digestion protocol, and the compounds were determined by HPLC-PDA-MS/MS. A total of 13 compounds were identified in all tests. After in vitro digestion, the relative bioaccessibility of carotenoids and chlorophylls ranged from 4 to 58%. The qualitative profile of carotenoids reflected the initial sample, with all-E-zeaxanthin (57.2%) being the most bioaccessible compound, followed by all-E-neochrome (31.26%), the latter being reported for the first time in the micellar fraction. On the other hand, among the chlorophylls only pheophytin a (15.01%) was bioaccessible. Furthermore, a chlorophyll derivative (Hydroxypheophytin a’) was formed after in vitro digestion. Considering all compounds, xanthophylls (12.03%) and chlorophylls (12.22%) were significantly (p < 0.05) more bioaccessible than carotenes (11.22%). Finally, the considerable individual bioaccessibilities found, especially for zeaxanthin, demonstrate the bioactive potential of this bioresource. However, the large reduction in the totality of compounds after in vitro digestion suggests that additional technological strategies should be explored in the future to increase the efficiency of micellarization and enhance its bioactive effects.

Comparative Evaluation on the Bioaccessibility of Citrus Fruit Carotenoids In Vitro Based on Different Intake Patterns.

The intake pattern has a great impact on the bioaccessibility of carotenoids from citrus fruit. Here, we compared the bioaccessibility of carotenoids from fresh citrus fruit (FC), fresh citrus juice (FCJ), and not-from-concentrate citrus juice (NCJ) and analyzed the influencing factors. The results demonstrated that particle size, viscosity, and some active components of the samples during digestion are potential factors affecting the bioaccessibility of carotenoids. The total carotenoid bioaccessibility of NCJ (31.45 ± 2.58%) was significantly higher than that of FC (8.11 ± 0.43%) and FCJ (12.43 ± 0.49%). This work demonstrates that NCJ is an appropriate intake pattern to improve the bioaccessibility of carotenoids from citrus fruit. The findings also suggest that adjustment of food intake patterns is an effective way to improve the digestion and absorption of nutrients.

Spray-dried and freeze-dried protein-spinach particles; effect of drying technique and protein type on the bioaccessibility of carotenoids, chlorophylls, and phenolics

The effects of protein carrier and drying technique on the concentration and bioaccessibility of lipophilic compounds (lutein, β-carotene, chlorophylls a and b) and hydrophilic flavonoids in freeze-dried (FD) or spray-dried (SD) spinach juice and protein-spinach particles were investigated. Carotenoid and chlorophyll contents were highest in FD spinach juice without protein (147 and 1355 mg/100 g, respectively). For both SD and FD protein-spinach particles, SPI best protected carotenoids and chlorophylls (123 and 1160 mg/g, respectively), although the bioaccessibility of lipophilic compounds in WPI particles was higher than SPI particles (p < 0.05). For flavonoids, the drying technique was more important than the type of carrier, since FD particles had higher total flavonoids than SD. However, SD particles had higher bioaccessibility for most flavonoids (40–90 %) compared to FD (<20 %). The drying method and protein carrier can be designed to produce protein-spinach ingredients with desired concentration of compounds and bioaccessibility.

Fabrication of nanoemulsion delivery system with high bioaccessibility of carotenoids from Lycium barbarum by spontaneous emulsification.

The interest in incorporating carotenoids into foods and beverages is growing due to their potential health benefits. However, the poor water solubility and low bioavailability of carotenoids are still challenges in food application. This work aimed to study the influence of system composition and preparation conditions on the physical properties of carotenoids‐loaded nanoemulsions prepared by spontaneous emulsification. Furthermore, the bioaccessibility of carotenoids in the nanoemulsions was evaluated. The nanoemulsions with the smallest droplet size were produced when the ratio of Span 80:Tween 80 was 1.5:8.5. The droplet size increased slightly with the increase of organic phase content (24%–40%). The droplet size decreased gradually with the increase of stirring speed (200–1000 rpm (revolutions per minute)). The ratio of mixed surfactants and surfactant‐to‐oil ratio (SOR) had an appreciable impact on the droplet size. Carotenoids‐loaded nanoemulsions with small mean droplet size (d < 50 nm) could be prepared with the optimized conditions. The initial digestion rate decreased as the SOR increased. The bioaccessibility could reach up to about 80% at SOR=2–5 in vitro digestion. These results have important implications for the design of effective delivery systems to encapsulate carotenoids and other lipophilic bioactive components in food applications.

Bioactivity and Bioaccessibility of Bioactive Compounds in Gastrointestinal Digestion of Tomato Bagasse Extracts.

A nutrient-rich diet is a key to improving the chemical signals, such as antioxidants, which modulate pathogens’ resistance in the gut and prevent diseases. A current industrial problem is the generation of undervalued by-products, such as tomato bagasse, which are rich in bioactive compounds and of commercial interest (carotenoids and phenolic compounds). This work analyzed the effect of gastrointestinal digestion on the bioactivity and bioaccessibility of carotenoids and phenolic compounds from tomato bagasse extracts. Thus, the extraction by ohmic heating (OH) technology was compared with conventional (organic solvents). The results showed that the main phenolic compounds identified by UPLC-qTOF-MS were p-coumaric acid, naringenin, and luteolin. A higher recovery index for total phenolic compounds throughout the gastrointestinal digestion was observed for OH while for carotenoids, a strong reduction after stomach conditions was observed for both extracts. Furthermore, colon-available fraction exhibited a prebiotic effect upon different Bifidobacterium and Lactobacillus, but a strain-dependent and more accentuated effect on OH. Thus, the extraction technology highly influenced bioaccessibility, with OH demonstrating a positive impact on the recovery of bioactive compounds and related health benefits, such as antioxidant, anti-hypertensive, prebiotic, and anti-inflammatory properties. Of these properties, the last is demonstrated here for the first time.

Enhancement of the in vitro bioavailable carotenoid content of a citrus juice combining crossflow microfiltration and high-pressure treatments

High-pressure treatments combined with crossflow microfiltration were used to obtain citrus concentrates enriched in carotenoids. The aim of this study was to investigate the effect of this process combination on carotenoid bioaccessibility and uptake by intestinal Caco-2 cells. Two high-pressure processes, high hydrostatic pressure treatment (HHP) and ultra-high-pressure homogenization (UHPH) were compared to conventional pasteurization. Processing effects on carotenoid content and bioaccessibility, on physicochemical and structural characteristics of the product, on methylation degree of pectins and micelle size after in vitro digestion were assessed. UHPH at 400 MPa drastically enhanced carotenoid bioaccessibility compared to HHP and pasteurization. Moreover, carotenoid uptake by Caco-2 cells was significantly improved by UHPH underlining the importance of the micelle size after in vitro digestion and the degree of methylation of pectins in this uptake. Finally, the in vitro bioavailable carotenoid content of different concentrates was evaluated, taking into account carotenoid content, bioaccessibility and uptake. Combining crossflow microfiltration with UHPH increased by 4–6 fold the bioavailable carotenoid content in the final product. The process led to a concentrate of high nutritional quality compared to the original juice, raw or pasteurized concentrates.

Bioaccessibility of carotenoids (β-carotene and lutein) from intact and disrupted microalgae (Chlamydomonas reinhardtii)

Chlamydomonas reinhardtii (C. reinhardtii) has a potential as a novel source for food/feed because it contains several constituents including bioactive compounds. However, its multilayer cell wall (hydroxyproline-rich glycoprotein [HRPGs]) may restrict the bioaccessibility of its nutrients. Therefore, using disruption techniques such as hydrodynamic cavitation (HDC) can be useful for assessing single cell compounds. This work aims to evaluate the impact of HDC on the bioaccessibility of carotenoids (β-carotene and lutein) from C. reinhardtii. Our results illustrated that digestive enzymes cannot fully break down the cell walls beside HDC process generates their significant change. The intact C. reinhardtii (ICR) and disrupted C. reinhardtii (DCR) have a comparable lutein bioaccessibility, in contrast, DCR decreased the biocessibility of β-carotene. HDC decreased the biocessibility of β-carotene in the small intestine although 37% of total carotenoids from DRC were absorbed.

Bioaccessibility and uptake by Caco-2 cells of carotenoids from cereal-based products enriched with butternut squash (Cucurbita moschata L.)

Enriching cereals-based products with bioactive compounds is a valuable strategy to improve product quality. We studied carotenoid bioaccessibility and intestinal uptake from a pumpkin-enriched porridge, cookies and sponge cakes by using in vitro digestion coupled with Caco-2 cell uptake. Among the carotenoids recovered in different products, α-carotene was the most important abundant one. However, lutein displayed a significantly higher bioaccessibility compared to α-carotene and β-carotene in baked products (up to 10.28% compared to 1.22% and 0.88%, respectively). α-Carotene was the only carotenoid recovered in Caco-2 cells after micelle incubation. Cookie micelles led to the highest percentage of α-carotene cell uptake (2.33% and 1.38% for cookies with butter and cookies with vegetable oil, respectively) compared to the other baked products, followed by dry pumpkin puree micelles (1.31%). Overall, our data show that both bioaccessiblity and cell uptake of carotenoids from cereal-based products are variable and highly depend on food formulation and structure.

Assessment of in vitro bioaccessibility of carotenoids and phenolic compounds in a model milk-mandarine beverage.

Mandarine juice is one of the richest sources of β-cryptoxanthin and flavonoids, which have been positively associated with bone mineral density. Carotenoids are lipophilic isoprenoid compounds with a complex absorption process that can be affected by different factors. In this study, we have evaluated the effect of the food matrix on the in vitro bioaccessibility of carotenoids and phenolic compounds in a model milk-mandarine beverage (MMB). MMBs were formulated with mandarine juice and different dairy products to achieve three fat levels (0.2%, 1.7% and 3.2%) and three calcium levels (120, 310 and 500 mg Ca2+ per 100 ml). The bioaccessibility was evaluated using a harmonised in vitro digestion method. The results showed that the content of milk fat increased the bioaccessibility in vitro of phenolic compounds (p < 0.05), while a moderate fat level (1.7%) resulted in the highest bioaccessibility for bioactive carotenoids. On the other hand, calcium fortification at the highest level (500 mg Ca2+ per 100 mL) decreased the bioaccessibility of bioactive carotenoids from 76% to 43% (66% for the major β-cryptoxanthin) compared to the lower calcium fortification level (120 mg Ca2+ per 100 mL). The bioaccessibility of hesperidin, the main flavanone in mandarine juice, was significantly (p < 0.05) reduced in the MMB with the highest calcium level. The bioaccessibility of carotenoids and phenolic compounds is affected by fat and calcium levels. When formulating functional beverages, the impact of the formulation should be carefully considered to optimize the bioaccessibility of the bioactive compounds.

Effect of an Emulsified Formulation on Vegetable Carotenoid Bioaccessibility.

We investigated the effect of neutral lipids, polar lipids, and an emulsified formulation (EMF) on carotenoid bioaccessibility in an in vitro digestion assay of vegetables. These reagents enhanced carotenoid bioaccessibility. Contrary to our previous report, they also exhibited effects on lutein. Bile extracts/pancreatin concentrations also participated in the bioaccessibility. The EMF, which consisted of lower amounts of oil, had the same effect on lutein as rapeseed oil. These reagents also showed effects in the aging model, with more reduced bile extract/pancreatin concentrations, suggesting that lipids and EMF contributed to carotenoid bioaccessibility in bile/pancreatic juice secretions due to aging and disease.

A guide for the evaluation of in vitro bioaccessibility of carotenoids.

Ongoing efforts to improve the nutritional content of carotenoids in food sources to solve global health problems must also consider bioaccessibility and bioavailability of carotenoids. Carotenoid bioaccessibility encompasses carotenoid release from the food matrix, solubilization in lipid emulsion droplets, and transfer to mixed micelles for further absorption into the intestine. Bioavailability refers to the fraction of carotenoids which enters into circulation. To understand the mechanisms controlling bioaccessibility, in vitro digestion methods have been developed and are a useful approach to overcome some of the disadvantages associated with in vivo protocols. The INFOGEST protocol comprises three phases (oral, gastric and intestinal) to simulate adult human digestion of foods, as an international consensus for the conditions of static in vitro digestion. The last steps in any digestion protocol involve isolation of the target food compounds and subsequent analysis, steps not included in the INFOGEST protocol because they may differ depending on specific physical-chemical characteristics and quantification analysis of the target analyte. In this chapter, we describe the INFOGEST protocol which has been adapted for the analysis of carotenoid bioaccessibility, including determination and calculation of enzyme activities according to INFOGEST guidelines, removal of undigested material, collection of mixed micelles containing carotenoids, extraction, storage and subsequent identification and quantification by liquid chromatography analysis of both free and acylated carotenoids.

Bioaccessibility and intestinal cell uptake of carotenoids and chlorophylls differ in powdered spinach by the ingredient form as measured using in vitro gastrointestinal digestion and anaerobic fecal fermentation models.

Insights into food matrix factors impacting bioavailability of bioactive carotenoids and chlorophylls from fruits and vegetable ingredients are essential to understanding their ability to promote health. The stability and bioaccessibility of carotenoids and chlorophylls were assessed from dehydrated, spray-dried, freeze-dried and fresh spinach ingredient forms using in vitro models simulating upper gastrointestinal (GI) digestion and lower GI anaerobic fecal fermentation. Intestinal transport of bioaccessible bioactives from both upper and lower GI compartments was assessed using the Caco-2 human intestinal cell model. Differences in carotenoid and chlorophyll contents were observed between ingredient forms and these influenced bioaccessibility. Lower carotenoid and chlorophyll contents in spray dried spinach resulted in the lowest total bioaccessible content among all spinach treatments (5.8 ± 0.2 μmoles per g DW carotenoid and chlorophyll). The total bioaccessible content was statistically similar between freeze-dried (12.5 ± 0.6 μmoles per g DW), dehydrated (12.5 ± 3.2 μmoles per g DW), and fresh spinach (14.2 ± 1.2 μmoles per g DW). Post anaerobic fermentation, cellular accumulation of carotenoids was higher (17.57-19.52 vs. 5.11-8.56%), while that of chlorophylls was lower (3.05-5.27 vs. 5.25-6.44%), compared to those observed following upper GI digestion. Collectively, these data suggest that spinach forms created by various drying technologies deliver similar levels of bioaccessible spinach bioactives and that the lower GI tract may serve as a site for significant absorption fostered by interactions with gut microbial communities that liberate additional bioactives from the spinach matrix.

Effect of cooking duration on carotenoid content, digestion and potential absorption efficiencies among refined semolina and whole wheat pasta products.

The bioaccessibility of carotenoids varies among different foods due to factors such as food matrix composition and type or extent of processing. Hence it is important to understand the extent to which these factors influence carotenoid bioaccessibility after the consumption and digestion of food. This study evaluated the carotenoid content, micellization efficiency, digestive stability, antioxidant activity and bioaccessibility of carotenoids as impacted by wheat cultivar and cooking duration among whole wheat flour (WWF) and refined semolina (RS) pasta. WWF and RS pasta were processed from three durum wheat cultivars (AAC Spitfire, CDC Precision, and Transcend) and cooked to al dente (Al), fully cooked (FCT) or overcooked (OC). The study showed that the wheat cultivar and cooking duration were significant functions of bioaccessible lutein in RS samples while only the cultivar influenced the bioaccessibility of zeaxanthin and lutein in WWF samples. In both WWF and RS, the effect of the cultivar on the bioaccessibility of lutein and zeaxanthin was similar and was as follows: Transcend > CDC Precision > AAC Spitfire. Cooking to Al significantly caused an increment in bioaccessible lutein in RS samples regardless of the wheat cultivar. This influence of cooking duration (Al > FCT > OC) was inversely related to the lutein concentrations in undigested pasta (OC = FCT > Al). DPPH scavenging activity among WWF samples was about 2-fold greater or more than that of RS samples regardless of the cultivar or cooking duration before and after digestion. Our data suggest that the effect of wheat cultivar and cooking duration modulates the bioaccessibility and antioxidant activity of RS and WWF pasta products.

A fast and simplified method to estimate bioaccessibility of carotenoids from plant tissues.

Carotenoids are lipophilic isoprenoids with roles in photosynthesis and signaling. Dietary carotenoids are nutritionally relevant as precursors of retinoids (including vitamin A). These pigments also provide health benefits as anti-oxidative, anti-inflammatory or anti-tumor agents, among other biological functions. Such health-related advantages have spurred a strong interest in the biofortification of food products with carotenoids. Most biotechnological approaches have been carried out in plants because dietary carotenoids are primarily obtained from fruits and vegetables. Successful examples abound in the literature but in most cases a critical aspect is neglected: bioaccessibility. A higher content of carotenoids in a given plant product does not necessarily mean an improved dietary intake because these lipophilic compounds must be released from the food and incorporated into intestinal micelles to reach the sites of action in the human body. Bioaccessibility refers to the percentage of the carotenoid that is released from the food matrix during digestion and incorporated into micelles in the gastrointestinal tract. Bioaccessibility substantially changes depending on the physicochemical context and subcellular environment where carotenoids accumulate within plant cells. Here, we present a fast, simplified, inexpensive and efficient in vitro method to estimate bioaccessibility that has been adapted to the requirements and equipment of typical plant molecular biology labs. The availability of this protocol should improve biotechnological efforts aimed at carotenoid biofortification by complementing compositional improvements with bioaccessibility data to better estimate the nutritional value of the newly generated functional food.

Micelle separation conditions based on particle size strongly affect carotenoid bioaccessibility assessment from juices after in vitro digestion

For assessing the carotenoid bioaccessibility during in vitro digestion, obtaining the micelle fraction that can diffuse through the mucin layer according to the particle size is an important step. However, the accuracy of the various approaches to obtaining the right fraction of micelles described in literature has not been investigated. In many studies the reported bioaccessible fraction might therefore be over- or underestimating the real bioaccessibility. The present study aimed to fill this gap and give approaches to get accurate data on the bioaccessible fraction from samples with different properties. Results illustrated that optimizing the centrifugal speed and duration of the digesta are essential in obtaining the micelle fraction. Different digesta have different optimum centrifugal parameters to obtain the bioaccessible fraction. 6,000 rpm and 40 min was selected as the optimum centrifugal parameter for combined juice (CJ). 6,000 rpm and 60 min was the optimum centrifugal parameter for CJ with oil, and CJ with emulsion using non-ionic emulsifier. 8,000 rpm and 20 min was the optimum centrifugal parameter for CJ with emulsion using ionic emulsifier. Polygalacturonanase (PG)-digested systems required higher centrifugal speed (10,000 rpm) compared with CJ-based systems (6,000 rpm or 8,000 rpm). A prediction model to determine the optimal centrifugation speed/time from the properties of the intestinal digesta was developed. Sample preparation conditions strongly affect carotenoid bioaccessibility assessment from juices during in vitro digestion. Based on these results, it is highly recommended to perform an optimized preparation procedure for bioaccessible fraction prior to carotenoid bioaccessibility analysis.

Effects of dietary fats on the bioaccessibility and bioavailability of carotenoids: a systematic review and meta-analysis of in vitro studies and randomized controlled trials.

Dietary fats are one of the well-known stimulators of carotenoid absorption, but the effects of the quantity and the type of dietary fats on carotenoid absorption have not yet been studied systematically. This review aimed to analyze data from both in vitro studies and randomized controlled trials (RCTs) to examine the effects of dietary fats on the bioaccessibility and bioavailability of carotenoids. A systematic search of 5 databases (Scopus, PubMed, Embase, CINAHL and the Cochrane Library) was conducted. In vitro studies and RCTs were selected according to the PICOS criteria and were reviewed independently by 2 investigators. Key study characteristics from the eligible in vitro studies and RCTs were extracted independently by 2 investigators using a standardized table. A total of 27 in vitro studies and 12 RCTs were included. The meta-regression of in vitro studies showed that the bioaccessibility of carotenoids, except for lycopene, was positively associated with the concentration of dietary fats. The meta-analysis of RCTs showed that the bioavailability of carotenoids was enhanced when a higher quantity of dietary fats was co-consumed. Moreover, fats rich in unsaturated fatty acids resulted in greater improvement in carotenoid bioavailability (SMD 0.90; 95%CI, 0.69-1.11) as compared with fats rich in saturated fatty acids (SMD 0.27; 95%CI, 0.08-0.47). Co-consuming dietary fats, particularly those rich in unsaturated fatty acids, with carotenoid-rich foods can improve the absorption of carotenoids. PROSPERO registration number CRD42020188539.

Citrus flavanones enhance the bioaccessibility of β-carotene by improving lipid lipolysis and incorporation into mixed micelles

Flavonoids can influence the bioaccessibility of carotenoids. In this study, the effect of citrus flavanones on β-carotene (Bc) bioaccessibility, lipid lipolysis and Bc micellarization were investigated. The results show that citrus flavanones significantly increased the bioaccessibility of Bc, made it from 15.85% to 19.67% (p < 0.05). The extent hydrolysis of different oil was significantly increased in the presence of citrus flavanones. In the case of soybean oil, addition of hesperetin (Hes) increased the extent hydrolysis of oil by 19.2% for 120 min (p < 0.05). Addition of citrus flavanones promoted the Bc micellarization. Data showed that citrus flavanones resulted in decrease of particle size and increase the absolute value of the emulsion ζ-potential, which could be partially responsible for the increase of hydrolysis of lipid and the Bc micellarization. Furthermore, cell experiments could clearly show that citrus flavanones can enhance the absorption of Bc in cells.

Whey- and Soy Protein Isolates Added to a Carrot-Tomato Juice Alter Carotenoid Bioavailability in Healthy Adults.

Recent findings suggested that proteins can differentially affect carotenoid bioaccessibility during gastro-intestinal digestion. In this crossover, randomized human trial, we aimed to confirm that proteins, specifically whey- and soy-protein isolates (WPI/SPI) impact postprandial carotenoid bioavailability. Healthy adults (n = 12 males, n = 12 females) were recruited. After 2-week washout periods, 350 g of a tomato-carrot juice mixture was served in the absence/presence of WPI or SPI (50% of the recommended dietary allowance, RDA ≈ 60 g/d). Absorption kinetics of carotenoids and triacylglycerols (TAGs) were evaluated via the triacylglycerol-rich lipoprotein (TRL) fraction response, at timed intervals up to 10 h after test meal intake, on three occasions separated by 1 week. Maximum TRL-carotenoid concentration (Cmax) and corresponding time (Tmax) were also determined. Considering both genders and carotenoids/TAGs combined, the estimated area under the curve (AUC) for WPI increased by 45% vs. the control (p = 0.018), to 92.0 ± 1.7 nmol × h/L and by 57% vs. SPI (p = 0.006). Test meal effect was significant in males (p = 0.036), but not in females (p = 0.189). In males, significant differences were found for phytoene (p = 0.026), phytofluene (p = 0.004), α-carotene (p = 0.034), and β-carotene (p = 0.031). Cmax for total carotenoids (nmol/L ± SD) was positively influenced by WPI (135.4 ± 38.0), while significantly lowered by SPI (89.6 ± 17.3 nmol/L) vs. the control (119.6 ± 30.9, p < 0.001). Tmax did not change. The results suggest that a well-digestible protein could enhance carotenoid bioavailability, whereas the less digestible SPI results in negative effects. This is, to our knowledge, the first study finding effects of proteins on carotenoid absorption in humans.

High-Pressure Processing of Kale: Effects on the Extractability, In Vitro Bioaccessibility of Carotenoids & Vitamin E and the Lipophilic Antioxidant Capacity.

High pressure processing (HPP) represents a non-thermal preservation technique for the gentle treatment of food products. Information about the impact of HPP on lipophilic food ingredients (e.g., carotenoids, vitamin E) is still limited in more complex matrices such as kale. Both the variation of pressure levels (200–600 MPa) and different holding times (5–40 min) served as HPP parameters. Whereas a slightly decreasing solvent extractability mostly correlated with increasing pressure regimes; the extension of holding times resulted in elevated extract concentrations, particularly at high-pressures up to 600 MPa. Surprisingly, slightly increasing bioaccessibility correlated with both elevated pressures and extended holding times, indicating matrix-dependent processes during in vitro digestion, compared to results of extractability. Moreover, the verification of syringe filters for digest filtration resulted in the highest relative recoveries using cellulose acetate and polyvinylidene difluoride membranes. The α-tocopherol equivalent antioxidant capacity (αTEAC) and oxygen radical antioxidant capacity (ORAC) assays of treated kale samples, chopped larger in size, showed increased antioxidant capacities, regarding elevated pressures and extended holding times. Consequently, one may conclude that HPP was confirmed as a gentle treatment technique for lipophilic micronutrients in kale. Nevertheless, it was indicated that sample pre-treatments could affect HP-related processes in food matrices prior to and possibly after HPP.

Turmeric, red pepper, and black pepper affect carotenoids solubilized micelles properties and bioaccessibility: Capsaicin/piperine improves and curcumin inhibits carotenoids uptake and transport in Caco-2 cells.

This study aimed to evaluate the role of spices/spice active principles on physical, biochemical, and molecular targets of bioaccessibility/bioavailability. Carotenoids-rich micellar fraction obtained through simulated digestion of green leafy vegetables (GLV) with individual or two/three combinations were correlated to their influence on bioaccessibility, cellular uptake, and basolateral secretion of carotenoids in Caco-2 cells. Results suggest that carotenoids' bioaccessibility depends on micelles physicochemical properties, which is affected due to the presence of co-treated dietary spices and their composition. Increased bioaccessibility of β-carotene (BC) and lutein (LUT) is found in GLV (spinach) digested with turmeric (TM) than red pepper (RP) and black pepper (BP). In contrast, enhanced cellular uptake and secretion of BC and LUT-rich triglyceride-rich lipoprotein is observed in the presence of RP and BP compared to the control group. In contrast, TM inhibited absorption, while retinol levels significantly reduced in the presence of TM and RP than BP. Control cells have indicated higher cleavage of β-carotene to retinol than the spice-treated group. Besides, spice active principles modulate facilitated transport of carotenoids by scavenger receptor class B type 1 (SR-B1) protein. The effect of spices on carotenoids' bioavailability is validated with active spice principles. Overall, carotenoids' bioavailability (cellular uptake and basolateral secretion) was found in the following order of treatments; piperine>capsaicin>piperine + capsaicin>curcumin + capsaicin + piperine>control>turmeric. These findings suggested that the interaction of specific dietary factors, including spice ingredients at the enterocyte level, could provide greater insight into carotenoid absorption. PRACTICAL APPLICATION: Spices/spice active principles play a role in the digestion process by stimulating digestive enzymes and bile acids secretion. Since carotenoids are lipid soluble and have low bioavailability, spice ingredients' influence on intestinal absorption of carotenoids is considered crucial. Hence, understanding the interaction of co-consumed spices on the absorption process of carotenoids may help to develop functional foods/formulation of nutraceuticals to improve their health benefits.