Air-dried capsicum annuum var. acuminatum medium and big: Determination of bioactive constituents, antioxidant activity and carbohydrate-hydrolyzing enzymes inhibition

Metabolic Variation among Fruits of Different Chili Cultivars (Capsicum spp.) Using HPLC/MS

Chilies are widely cultivated for their rich metabolic content, especially capsaicinoids. In our study, we determined individual sugars, organic acids, capsaicinoids, and total phenolic content in pericarp, placenta, and seeds of Capsicum annuum L., Capsicum chinense Jacq. and Capsicum baccatum L. by HPLC/MS. Dry weight varied in the cultivar 'Cayenne', with the first fruit having the lowest dry weight, with 4.14 g. The total sugar content and organic acid content did not vary among the fruits of all three cultivars. The cultivar 'Cayenne' showed differences in total phenolic and capsaicinoid content between fruits in the placenta, with the first fruit having the highest content of total phenolics (27.85 g GAE/kg DW) and total capsaicinoids (16.15 g/kg DW). Of the three cultivars studied, the cultivar 'Habanero Orange' showed the least variability among fruits in terms of metabolites. The content of dihydrocapsaicin, nordihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin in the seeds of the second fruit was higher than that of the first fruit of the cultivar 'Bishop Crown'. The results of our study provided significant insight into the metabolomics of individual fruits of the same chili plant. We have thus increased our understanding of how certain metabolites are distributed between fruits at different levels of the same plant and different parts of the fruit. This could be further investigated when chilies are exposed to different environmental stresses.

In vitro α-amylase and α-glucosidase enzyme inhibition and antioxidant activity by capsaicin and piperine from Capsicum chinense and Piper nigrum fruits

In the present study, α-amylase and α-glucosidase inhibitory effect and antioxidant activity of capsaicin and piperine from the ethanolic extract of Capsicum chinense (EECch) and Piper nigrum (EEPn) fruits were investigated. Results revealed that EECch exhibited the highest phenolic (154 mg GAE/100 g of tissue) and flavonoid content (75 mg RtE/100 g of tissue) in comparison with EEPn. The predominant compound detected in EECch and EEPn by GC-EIMS analysis was the capsaicin and piperine, respectively. The capsaicin and piperine showed the highest α-amylase and α-glucosidase inhibitory effect and antioxidant activity rather than extracts. The EEPn (IC₅₀= 216 µg/mL) and piperine (IC₅₀= 105 µg/mL) present a highest α-amylase inhibitory effect, while the EECch (IC₅₀= 225 µg/mL) and capsaicin (IC₅₀= 117 µg/mL) showed highest anti-α-glucosidase activity. Molecular docking established that capsaicin and piperine bind at the α-glucosidase and α-amylase through hydrophobic interactions, hydrogen bond, and charge interactions with amino acid residues. The enzyme inhibitory activity and antioxidant properties exhibited by EECch and EEPn could be attributed to the capsaicin and piperine content and other compounds present such as phenolic compounds and flavonoids. These fruits are potential sources of natural antioxidant agents and α-amylase and α-glucosidase inhibitors.

Carotenoids of Capsicum Fruits: Pigment Profile and Health-Promoting Functional Attributes

Pepper of the Capsicum species is a common ingredient in various food preparations by different cultures worldwide. The Capsicum is recognised by its five main domesticated species, namely Capsicum annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens. The genetic diversity in Capsicum offers fruits in wide ranges of morphology and carotenoid profile. Carotenoids enhance the value of pepper from a nutritional standpoint, despite being commonly prized for the pharmacologically active pungent capsaicinoids. Carotenoids of pepper comprise mainly of the unique, powerful and highly stable capsanthin and capsoroubin, together with β-carotene, β-cryptoxanthin, lutein, zeaxanthin, antheraxanthin and violaxanthin. These carotenoids are present at diverse profile and varying levels, biosynthetically connected to the fruit maturity stages. This review describes the health-promoting functional attributes of the carotenoids that are mainly associated with their excellent role as lipophilic antioxidants. Capsicum as a great source of carotenoids is discussed in the aspects of main domesticated species, biosynthesis, pigment profile, antioxidant activity and safety. Findings from a number of in vitro, in vivo and clinical studies provided appreciable evidence on the protective effects of pepper’s carotenoids against degenerative diseases. Hence, pepper with its functional carotenoids might be recommended in health-promoting and disease preventing strategies.

Non-Pungent n-3 Polyunsaturated Fatty Acid (PUFA)-Derived Capsaicin Analogues as Potential Functional Ingredients with Antioxidant and Carbohydrate-Hydrolysing Enzyme Inhibitory Activities

N-Eicosapentaenoyl vanillylamine (EPVA) and N-docosahexaenoyl vanillylamine (DHVA), derived from n-3 polyunsaturated eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, were studied for their potential antioxidant and carbohydrate-hydrolysing enzyme inhibitory activities together with capsaicin and the corresponding n-3 polyunsaturated fatty acids (PUFAs). The antioxidant potential was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay, β-carotene bleaching test, and ferric reducing ability power (FRAP). In the ABTS assay the following trend of potency could be observed EPVA > DHVA ≥ capsaicin. In addition, except for the FRAP test, all samples showed a greater activity than the positive controls used as reference compounds in the antioxidant assays. Both EPVA and DHVA showed half maximal inhibitory concentration (IC₅₀) values much lower than acarbose, which was used as the reference drug in the carbohydrate-hydrolysing enzyme inhibitory activity assays. It is interesting to note that structural changes in capsaicin derivatives had higher impacts on α-glucosidase than on α-amylase inhibition. Taken together, our data suggest that both EPVA and DHVA, which are not limited in compliance-related considerations with respect to capsaicin, due to absence of pungency, could be proposed as functional ingredients for the development of products for the management of type II diabetes and border-line hyperglycaemic patients.

Progression of the Total and Individual Capsaicinoids Content in the Fruits of Three Different Cultivars of Capsicum chinense Jacq

The evolution of individual and total capsaicinoids content in three pepper varieties of Capsicum chinense Jacq. (‘Bode’ (B), ‘Habanero’ (H), and ‘Habanero Roxo’ (Hr)) during fruit ripening was studied. The five major capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin) were extracted using ultrasound-assisted extraction and the extracts were analysed by ultra-performance liquid chromatography with fluorescence detection (UHPLC-Fl). The plants were grown in a glasshouse and sampled every 7 days until over-ripening. As expected, the results indicated that the total capsaicinoids content increases during the ripening of pepper fruits. The maximum contents of capsaicinoids were reached at different fruit development stages depending on the cultivar. The ‘Habanero Roxo’ pepper presented the greatest total capsaicinoids content (3.86 mg g−1 fresh weigh, F.W.), followed by the ‘Habanero’ pepper (1.33 mg g−1 F.W.) and ‘Bode’ pepper (1.00 mg g−1 F.W.). In all the samples, capsaicin represented more than 80% of the total capsaicinoids content. Due to the high variability observed in the evolution of capsaicinoids content over the ripening process, this work intends to contribute to the existing knowledge on this aspect in relation to the quality of peppers.

In vitro assessment of the bioaccessibility of carotenoids from sun-dried chilli peppers

Chilli peppers have been recognized as an excellent source of antioxidants as they are rich in bioactive phytochemicals such as carotenoids which are known to exert various beneficial effects in vivo. Absorption is an important factor in the determination of the potential biological effects of carotenoids. The bioaccessibility of a food constituent such as a carotenoid represents its potential to be absorbed in humans. There is very limited information in the literature regarding the content and bioaccessibility of carotenoids from dried peppers. Therefore, the objectives of the present study were: first, to determine the carotenoid content of 20 varieties of red, orange or yellow coloured sun-dried chilli peppers belonging to either of four Capsicum species (annuum, baccatum, chinense and chacoense); and second, to quantify the carotenoid micellarization (bioaccessibility) following an in vitro digestion procedure. Red peppers had a higher carotenoid content and bioaccessibility than either the orange peppers or yellow pepper. Xanthophylls showed greater bioaccessibility than carotenes. Our findings confirm that dried chilli peppers are a good source of carotenoids.

In vitro investigation of the bioaccessibility of carotenoids from raw, frozen and boiled red chili peppers (Capsicum annuum)

BACKGROUND

Carotenoid-rich foods are associated with antioxidant activity and the ability to alleviate chronic diseases.

PURPOSE

The present study investigated the effect of processing on the content and bioaccessibility of carotenoids from 13 cultivars of red chili pepper (Capsicum annuum).

METHODS

Carotenoids in chili peppers were analyzed before an in vitro digestion process. The portion of carotenoid transferred to the micelle fraction (bioaccessibility) was also quantified.

RESULTS

β-Carotene, β-cryptoxanthin, capsanthin and antheraxanthin were the most abundant carotenoids. Zeaxanthin, violaxanthin, neoxanthin and lutein were detected at lower concentrations. In general, freezing and boiling reduced carotenoid contents. Capsanthin and zeaxanthin had the highest bioaccessibility at an average value from 36 to 40%, followed by antheraxanthin (26%). Bioaccessibility of β-cryptoxanthin, violaxanthin and β-carotene was lower, averaging 6.1, 4.8 and 4.0%, respectively. Neoxanthin and lutein were not detected in micelles. Freezing increased the bioaccessibility of capsanthin, zeaxanthin, antheraxanthin, β-cryptoxanthin and violaxanthin; β-cryptoxanthin bioaccessibility increased and capsanthin and zeaxanthin bioaccessibility decreased following boiling.

CONCLUSIONS

Differences in the contents and bioaccessibility of carotenoids in 13 C. annuum cultivars and between the processed methods were herein evidenced.