The Influence of In Vitro Gastrointestinal Digestion on the Chemical Composition and Antioxidant and Enzyme Inhibitory Capacities of Carob Liqueurs Obtained with Different Elaboration Techniques

Identification, Bioaccessibility, and Antioxidant Properties of Phenolic Compounds in Carob Syrup

Carob syrup is a brown, thick syrup produced from carob pulp that can be directly consumed or used as a sweetener, which also finds applications in folk medicinal practices. In this work, the quali-quantitative phenolic profile of five different carob syrups was elucidated before and after in vitro gastro-intestinal digestion. Moreover, the anti-oxidant properties of undigested and digested carob syrups were investigated. A total of 75 phenolic compounds were identified in undigested carob syrups. The most important phenolic compound in all the samples was gallic acid, the concentration of which ranged between 54.28 and 117.73 mg/100 g. Additional compounds belonging to the classes of hydroxybenzoic acids (in particular glycosylated gallic acid derivatives), hydroxycinnamic acids, and flavonoids (especially flavonols) were also identified. During in vitro gastric digestion, gallic acid mono- and di-hexosides were diglycosylated, releasing gallic acid, which was further degraded in ellagic acid through oxidative polymerization in the intestinal phase of the digestion. Ellagic acid was the major compound detected after in vitro gastro-intestinal digestion of carob syrups. With few exceptions, the anti-oxidant properties of carob syrup were preserved even after digestion. Carob syrup can be considered an important source of phenolic compounds with demonstrated positive effects on human health.

Ripening stage impacts nutritional components, antiglycemic potential, digestibility and antioxidant properties of grumixama (Eugenia brasiliensis Lam.) fruit

This study aimed to determine the nutritional components (macronutrients ans minerals) and α-amylase inhibition capacity of freeze-dried grumixama (Eugenia brasiliensis Lam) seeds (S) and pulp/peel (P) portions, at ripe and mid-ripe stages. In vitro digestion was also performed on S and P from grumixama to assess the bioaccessibility of total phenolic compound (TPC), flavonoids (TFC), and anthocyanins (TAC), as well as to examine their impact on antioxidant activity (DPPH, ABTS, FRAP). The ripening process impacts the bioactive compounds and individual phenolics of S and P portions. The ripe S was source of myricetin and exhibited higher antioxidant activity, while mid-ripe S was high in flavonoids and cinnamic acid with higher antiglycemic potential. Ripe P showed higher soluble fiber, carbohydrate, TAC, and caffeic acid content, whereas mid-ripe P had increased mineral content (calcium, potassium, manganese), catechin, and TPC. After in vitro digestion, the P portion showed a bioaccessibility of total phenolic content (TPC) and total flavonoid content (TFC) exceeding 40% at intestinal phase. In contrast, the S portions had better release of TPC and TFC and antioxidant activity at gastric phase. Considering the outstanding nutritional and biological properties of grumixama fruit, freeze-dried S and P portions from both ripening stages possess could be explored as valuable sources of nutrients and antioxidant compounds.

Nutritional, biochemical, and clinical applications of carob: A review

Carob is botanically called as Ceratonia siliqua and belongs to the Legumes family. The fruit is derived from hermaphrodite trees and hard in shape. The carob contains high sugar contents in pulp, fat in seed and minerals like potassium, calcium, and phosphorus are present in pods. Polyphenols and antioxidants are abundant in leaves and pods. It can be used for enhancing human health due to its high nutritional profile. Carob gum is used in the pharmaceutical industry in the form of pomades, anti-celiac ingredients, pills, and dental paste. The clinical carob can aid as an anti-cancer, anti-reflux, anti-diabetic, anti-diarrheal, anti-hyperlipidemia, anti-bacterial, anti-microbial, and anti-fungal. Nowadays, carob seeds are being used as an alternative to cocoa powder in food items whereas the leaves, pods, and seeds of carob are also historically used as food for animal feed. However, these parts of carob are available in markets with reasonable prices. Carob production, though with a rising contribution, contributes to the local economy. In this sense, we can incorporate knowledge on the chemical properties and the biological effect of carob fruits on human health. In this study, the supportive and health-promoting impacts of carob are discussed along with the clinical testing obtained from natural constituents of carob. In addition, further studies can be performed to extract and separate polyphenols and antioxidant potential for the development of functional that play a valuable role in pharmaceutical and food sectors.

Antioxidant and cytotoxic activity of red wine after in vitro simulated digestion in the presence of complex food matrix

The beneficial effect of moderate wine consumption is attributed to its micronutrients, especially polyphenols and largely depends on the digestion process. This work aimed to examine the influence of in vitro simulated digestion in the presence of complex food matrix on antioxidant and cytotoxic activity of red wine. The obtained results showed that total phenolic content of wine sample after in vitro digestion was higher compared to undigested wine, while the antioxidant activity of these samples was similar before and after digestion. Furthermore, it has been noticed that digested wine showed cytotoxic activity on SKBR3 breast adenocarcinoma cells near 20% after 72 h of treatment. This pioneering study that examined biological potential of in vitro digested wine in the presence of complex food matrix indicate that antioxidant and cytotoxic activity of red wine is preserved after digestion.

The Effect of Vibratory Grinding Time on Moisture Sorption, Particle Size Distribution, and Phenolic Bioaccessibility of Carob Powder

Carob pod powder, an excellent source of health-promoting substances, has found its use in a wide range of food products. Grinding conditions affect the physical and chemical properties of the powder, but their influence on the bioaccessibility of phenolic compounds in carob pod powder has not yet been determined. The carob pods were ground for 30-180 s in a vibratory grinder. The median values (D₅₀) of particle size decreased after 60 s of grinding (87.9 μm), then increased to 135.1 μm. Lightness showed a negative correlation with D₅₀ and a_w, while the values of redness and yellowness decreased with the reduction in particle size and water activity. The smaller the value of D₅₀, the higher the equilibrium moisture content of carob powder. Phenolic acids (vanillic, ferulic, cinnamic) and flavonoids (luteolin, naringenin, apigenin) were found in all samples of carob powder. The grinding time influenced their content in carob powder, with maximum values at 180 s. Similar observations were made when assessing antioxidant capacity. The in vitro digestion process only improved the bioaccessibility of catechin content in all samples. However, the bioaccessibility of the phenolic compounds and the total phenolic and flavonoid contents decreased with the increase in grinding time. Our findings revealed that the grinding of carob pods for 180 s improved the extractability of phenolics; however, their bioaccessibility was reduced. It is sufficient to ground the carob pod for 30 s, ensuring good availability of nutraceuticals and lower energy cost for grinding.

Bioaccessibility of phenolics from carob (Ceratonia siliqua L.) pod powder prepared by cryogenic and vibratory grinding

Carob pod powder prepared by cryogenic (CG) and vibratory grinding for 4 min (VG-4) and 8 min (VG-8) was evaluated for its antioxidant properties, and phenolic content. The bioaccessibility of phenolics was determined after the oral, gastric, and intestinal digestion phases in vitro. CG carob powder had a higher total phenolic content (6.46 mg gallic acid/g) and antioxidant capacities in terms of DPPH (15.60 mg Trolox/g) and ABTS (28.58 mg Trolox/g) assays. Quercitrin (44.54-64.68 μg/g) and cinnamic acid (27.48-31.40 μg/g) were the most abundant phenolics in all carob powder samples determined by liquid chromatography. The bioaccessibility of only ferulic acid (108%) had increased after digestion of the CG carob powder. Vibratory grinding (VG-4 and VG-8) improved the bioaccessibility of cinnamic acid (86-87%), vanillic acid (87-95%), quercitrin (33-34%), and naringenin (19-22%). A better bioaccessibility of phenolic constituents was observed for vibratory ground carob powder.

Particle Size Effect of Integral Carob Flour on Bioaccessibility of Bioactive Compounds during Simulated Gastrointestinal Digestion

Carob fruit is native to the Mediterranean region and produced mainly in Portugal, Italy, Morocco and Turkey. The production of the carob fruit in Portugal is highly extensive and sustainable. Currently, carob flour (CF) production is mainly achieved after pulp separation, despite it having been demonstrated that the seeds improve the extraction efficiency of bioactive compounds such as polyphenols, promoting human health. This study aimed to produce an integral CF through an innovative process and assess its physicochemical and bioactive properties at different particle sizes throughout simulated gastrointestinal tract (GIT) digestion. The sugar content profile obtained throughout GIT digestion indicated that sucrose, the sugar present at the highest concentration in undigested CF, was digested and broken down into simple sugars, namely glucose and fructose. The total phenolic content (TPC) and antioxidant activity obtained for the ≤100 µm fraction were in accordance and gastric digestion promoted an increase in the TPC value compared to the undigested sample. The >100 µm fractions displayed a distinct profile from the ≤100 µm fraction. This study showed that the particle size affects the sugar, antioxidant and total phenolic content of CFs and also their gastrointestinal tract digestion. The ≤100 µm fraction demonstrated the most suitable profile as a functional food ingredient.

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.

Microencapsulation and Bioaccessibility of Phenolic Compounds of Vaccinium Leaf Extracts

In recent years, Vaccinium spp. (bilberry-VMT, lingonberry-VVIT, and blueberry-VCS) have sparked particular interest for their prospective health benefits. The latest investigations have place them as important alternative sources of nutraceuticals as their leaves are the main by-products of berry harvesting. The present study is aimed at investigating the bioaccessibility of phenolic compounds from leaves of the Vaccinium species, both as microencapsulated powder and aqueous extracts, following exposure to in vitro simulated digestion. Moreover, the impact of maltodextrin and glucose microencapsulation carriers on the extracts’ phenolic content was assessed. Prior to encapsulation, the viscosity of the emulsions was shown at a shear stress of 50 s−1 dilatant and a Newtonian behaviour above this value with a final viscosity between 1.024 and 1.049 mPa·s. The final microencapsulation yield for the samples ranged between 79 and 81%. Although the microencapsulated forms presented a targeted release at the intestinal level, the phenolic content decreased after gastrointestinal digestion. The bioaccessibility of the microencapsulated extracts showed higher values than their non-encapsulated counterparts, with the highest value of 45.43% in the VVIT sample, followed by VCS with 41.07%. However, the non-encapsulated VCS sample presented high bioaccessibility after in vitro digestion (38.65%). As concluded, further in vivo research should be conducted on the leaves of the Vaccinium species.

Influence of elaboration process on chemical, biological, and sensory characteristics of European pennyroyal liqueurs

BACKGROUND

Mentha pulegium is an aromatic and medicinal plant used in different Mediterranean herb-based liqueurs, whose phytochemical composition depends on the elaboration technique used. The aim of this work was to investigate differences in the sensory, chemical, and biological characteristics of pennyroyal liqueurs elaborated by hydro-alcoholic (HI) and aqueous (AI) infusions, percolation (P), maceration (M), and distillation (D) techniques, and by the mixture of spirit with pennyroyal essential oil (EO). The volatile composition determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography coupled to flame ionization detection (GC-FID), the total phenolic (TPC) and flavonoid (TFC) contents, the antioxidant (AC), and enzyme (α-glucosidase, tyrosinase, and acetylcholinesterase) inhibitory capacities, and the sensory analysis by napping, were evaluated in the liqueurs obtained.

RESULTS

Monoterpenes and sesquiterpenes were the main volatiles present in liqueurs. The M, P, HI, and AI liqueurs showed the highest TPC, TFC, and AC values; and pulegone, the main hepatotoxic chemotype, was found in concentrations that gave rise to concern. The D and EO liqueurs stand out for their acceptable pulegone content and greater tyrosinase inhibition. Similar liqueur classifications were achieved by sensory analyses, and physico-chemical and biological analyses using multiple factor and principal component analyses, respectively.

CONCLUSION

These results are an important contribution to the identification of the most appropriate elaboration conditions for herbal liqueurs with the healthiest chemical composition and functional properties. © 2020 Society of Chemical Industry.

Sustainability Opportunities for Mediterranean Food Products through New Formulations Based on Carob Flour (Ceratonia siliqua L.)

Carob flour is increasingly popular in innovative functional foods. Its main producers are Mediterranean countries, facing health and nutrition challenges, and difficulties in tackling climate change. This study aims at formulating innovative sustainable bakery products of high nutritional value while pleasing the consumer and addressing regional challenges. Hence, carob flour was obtained by grinding sun-dried carob pods, thus reducing the environmental impact, and preserving carob’s high nutraceutical value. Different bread formulations resulted from the blend of wheat flour with carob pulp (5, 10, 20, and 30%) and/or seed powder (5 and 10%), with no added fats, additives, or processing aids. New products were evaluated for their textural, chromatic, nutritional, aromatic, and hedonic properties. Carob is rich in aroma, antioxidants, and prebiotic fibers, and does not contain gluten, so when combined with wheat, the proportion of gluten in bread is reduced. Carob is also rich in minerals (4.16% and 2.00% ash, respectively in seed and pulp), and breadmaking seems to generate lesser furane derivatives than in white bread. In short, carob is typically Mediterranean and is a valuable local resource in the formulation of sustainable foods with high nutritional value, low carbon footprint, safe, healthy, tasty, and affordable, all at once.

GC-MS Metabolic Profile and α-Glucosidase-, α-Amylase-, Lipase-, and Acetylcholinesterase-Inhibitory Activities of Eight Peach Varieties

The inhibition of certain digestive enzymes by target food matrices represents a new approach in the treatment of socially significant diseases. Proving the ability of fruits to inhibit such enzymes can support the inclusion of specific varieties in the daily diets of patients with diabetes, obesity, Alzheimer's disease, etc., providing them with much more than just valuable micro- and macromolecules. The current study aimed atidentifying and comparing the GC-MS metabolic profiles of eight peach varieties ("Filina", "Ufo 4, "Gergana", "Laskava", "July Lady", "Flat Queen", "Evmolpiya", and "Morsiani 90") grown in Bulgaria (local and introduced) and to evaluate the inhibitory potential of their extracts towards α-glucosidase, α-amylase, lipase, and acetylcholinesterase. In order to confirm samples' differences or similarities, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were also applied to the identified metabolites. The results provide important insights into the metabolomic profiles of the eight peach varieties and represent a first attempt to characterize the peels of the peach varieties with respect to α-glucosidase-, α-amylase-, lipase-, and acetylcholinesterase-inhibitory activities. All of the studied peach extracts displayed inhibitory activity towards α-glucosidase (IC₅₀: 125-757 mg/mL) and acetylcholinesterase (IC₅₀: 60-739 mg/mL), but none of them affected α-amylase activity. Five of the eight varieties showed inhibitory activity towards porcine pancreatic lipase (IC₅₀: 24-167 mg/mL). The obtained results validate the usefulness of peaches and nectarines as valuable sources of natural agents beneficial for human health, although further detailed investigation should be performed in order to thoroughly identify the enzyme inhibitors responsible for each activity.

Carob Pulp: A Nutritional and Functional By-Product Worldwide Spread in the Formulation of Different Food Products and Beverages. A Review

Carob (Ceratonia siliqua L.) pod is a characteristic fruit from the Mediterranean regions. It is composed by seeds, the valuable part due to the extraction of locust bean gum, and the pulp, considered a by-product of the fruit processing industry. Carob pulp is a mixture of macro- and micronutrients, such as carbohydrates, vitamins and minerals, and secondary metabolites with functional properties. In the last few years, numerous studies on the chemical and biological characteristics of the pulp have been performed to encourage its commercial use. Its potential applications as a nutraceutical ingredient in many recipes for food and beverage elaborations have been extensively evaluated. Another aspect highlighted in this work is the use of alternative processes or conditions to mitigate furanic production, recognized for its toxicity. Furthermore, carob pulp’s similar sensorial, chemical and biological properties to cocoa, the absence of the stimulating alkaloids theobromine and caffeine, as well as its low-fat content, make it a healthier potential substitute for cocoa. This paper reviews the nutritional and functional values of carob pulp-based products in order to provide information on the proclaimed health-promoting properties of this interesting by-product.

Red beet (Beta vulgaris) and amaranth (Amaranthus sp.) microgreens: Effect of storage and in vitro gastrointestinal digestion on the untargeted metabolomic profile

This study aimed to investigate the combined effect of storage at 4 °C (10-days) and in vitro gastrointestinal digestion on the phytochemical profile of red beet (Beta vulgaris) and amaranth (Amaranthus sp.) microgreens. The untargeted profiling based on UHPLC-QTOF metabolomics allowed annotating 316 compounds, comprising mainly polyphenols and lipids. An impact of storage on the total phenolic content (TPC) was observed, with a maximum increase at 10-days of storage for both red beet (+1.3-fold) and amaranth (+1.1-fold). On the other hand, in vitro digestion of both red beet and amaranth microgreens produced a significant increase in TPC (36-88%), CUPRAC (27-40%), DPPH (6-43%), and BC (41-57%) to reach the maximum at 10 days of storage. Tyrosinase inhibitory potential also decreased following digestion. The combination of biochemical changes occurring in microgreen immature plants (likely in response to the harvest stress) with changes during digestion, determined the actual functional value of microgreens.

Use of Chemometrics for Correlating Carobs Nutritional Compositional Values with Geographic Origin

Carobs unique compositional and biological synthesis enables their characterization as functional foods. In the present study, 76 samples derived from fruit and seeds of carobs, with origin from the countries of the Mediterranean region (Cyprus, Greece, Italy, Spain, Turkey, Jordan and Palestine) were analyzed for their nutritional composition, in order to identify potential markers for their provenance and address the carobs' authenticity issue. Moisture, ash, fat, proteins, sugars (fructose, glucose, sucrose), dietary fibers and minerals (Ca, K, Mg, Na, P, Cu, Fe, Mn, Zn) were estimated following official methods. Due to the large number of data (76 samples × 17 parameters × 7 countries), chemometric techniques were employed to process them and extract conclusions. The samples of different geographical origin were discriminated with 79% success in total. The carobs from Cyprus, Italy and Spain were correctly classified without error. The main discriminators were found to be the dietary fibers, the carbohydrates and Cu, Zn and Mn, which emphasize their specific nutritional added value to the product and the country of origin impact. The results suggest that the proposed analytical approach is a powerful tool that enables the discrimination of carobs based on their country of origin. This research contributes to authenticity of carobs, adding value to local products.

Physicochemical and aromatic characterization of carob macerates produced by different maceration conditions

Carob liqueur is an alcoholic drink (minimum 15% v/v of ethanol and 100 g/L of sugar) typical for the Mediterranean countries. In the current work, carob macerate produced by maceration of carob pods in hydroalcoholic base at different maceration conditions was characterized for the first time based on its aroma compounds/profile, physicochemical parameters, and chromatic characteristics. The results confirm the migration process of bioactive compounds, aroma compounds, and sugars flowing from the carob pod to the hydroalcoholic base. Changes in ethanol concentration modify the physical properties of the solvent and influence the phenolic and aroma compounds extraction, color, and acidity of the obtained samples. The higher content of phenolic compounds was determinate in the samples obtained in the darkness. The amounts of phenols were in the range of some red fruit liqueurs or walnut liqueurs, and sugars (mostly sucrose) ranging between 96 and 107 g/L. Twenty-six (out of total 94) aroma compounds were detected in all samples, of which 17 esters, 3 alcohols, 4 ketones, and 2 acids. Low molecular weight ethyl esters, ethyl hexanoate, ethyl 2-methyl propanoate, ethyl octanoate, ethyl benzoate, ethyl butanoate, and ethyl cinnamate, were the most abundant. Carob pod maceration in 50% v/v hydroalcoholic base (1:5 solid to liquid ratio) in darkness at room temperature during 8 weeks can be recommended as optimal maceration conditions for production of the aromatic carob macerate with functional properties.