Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Developing Penicillium digitatum Management Strategies on Post-Harvest Citrus Fruits with Metabolic Components and Colonization of Bacillus subtilis L1-21

Citrus is among the most important plants in the fruit industry severely infected with pathogens. Citrus green mold caused by Penicillium digitatum is one of the most devastating diseases during post-harvest stages of citrus fruit. In this study, a potential endophyte Bacillus subtilis L1-21, isolated from healthy citrus plants, was assessed for its biocontrol activity against the pathogen P. digitatum. Based on an in vitro crosstalk assay, we suggested that B. subtilis L1-21 inhibits the pathogen with an inhibition zone of 3.51 ± 0.08 cm. Biocontrol efficacy was highest for the fermented culture filtrate of B. subtilis L1-21. Additionally, using GC-MS analysis, 13 compounds were detected in the extract of this endophyte. The culture filtrate in Landy medium could enlarge and deform pathogen spores and prevent them from developing into normal mycelium. Accordingly, the Landy culture filtrate of B. subtilis L1-21 was stable in the temperature range of 4–90 °C and pH of 3–11. Further, MALDI-TOF-MS for B. subtilis L1-21 detected surfactin, fengycin, bacillaene and bacilysin as potential antifungal compounds. GFP-tagged B. subtilis L1-21 easily colonized in citrus fruit peel and pulp, suggesting its role in eliminating the fungal pathogen. Altogether, it is highly expected that the production of antifungal compounds, and the colonization potential of B. subtilis L1-21 are required against the post-harvest P. digitatum pathogen on citrus fruit.

Profiling of Phenolic Compounds of Fruit Peels of Different Ecotype Bananas Derived from Domestic and Imported Cultivars with Different Maturity

Banana is one of the most produced and consumed fruits in the world and its fruit peel accounts for about 40% of the total fresh quantity of ripe fruit, which is usually regarded as waste and poses serious environmental hazards. However, it is a promising source of natural bioactive compounds including phenolic compounds. Determination of the phenolic compounds in fruit peel from different cultivars and subgroups over a range of maturities provides convincing information for making full use of them. This study developed a sensitive and reliable analytical method—ultra-high performance liquid chromatography—coupled with electrospray ionization tandem mass spectrometry (UPLC-MS/MS) for measuring phenolic compounds in fruit peel from different ecotype cultivars and subgroups with different maturity. The results showed that quinic acid had the highest concentration ratio among the main phenolic compounds in the green/ripe peel of all banana cultivars; among all banana cultivars, the total phenolic compound contents of green banana peel were significantly higher than that of ripe banana peel; the total phenolic compound contents in the green/ripe fruit peel of non-dessert bananas were significantly higher than that of dessert bananas (green: non-dessert banana 1.48 ± 0.44 mg/g vs. dessert banana 0.97 ± 0.12 mg/g; ripe: non-dessert banana 0.26 ± 0.13 mg/g vs. dessert banana 0.19 ± 0.06 mg/g). These data provide a basis for the rational utilization of phenolic compound extractions from banana peel with huge biomass in the next step.

Determination of Polyphenols Content and Antioxidant Activity of Citrus sinensis Fruit Peel

Citrus fruits have long been qualified as veritable foods in view of the many therapeutic benefits they bring to the body. Several researchers have stud-ied the relationship between the bioactive compounds of Citrus and the health benefits and reduction of the risk of disease. Citrus sinensis, used in the food industry and its extracts have also been used in traditional medicine to activate vital energy, circulation, and weight loss, and appetite control. However, limited efforts have been made on collecting data on antioxidant potential of peels orange from the northern region of Algeria. Our study, therefore, focuses on the evaluation of total polyphenols compounds and in vitro assessment of their antioxidant potential of peels orange from the northern region of Algeria. The ethyl acetate and n-butanolic fractions from peels orange have been tested for their antioxidant activities and their lipid peroxidation inhibiting effects. The total phenolic and flavonoids content showed high levels. The preliminary phytochemical screening of tannins, phenolic compounds, flavonoids, coumarin, and alkaloids was also used. DPPH assay possesses strong potency to scavenge free radicals. The NO. radi-cal scavenging test exerts a good inhibitory effect. Furthermore, orange peels have been shown to suppress the lipid peroxidation of linoleic acid. Results further revealed a strong correlation between antioxidant effects and polyphenolic compounds. The high antioxidant activity of peel orange suggests that it could serve as a good natural antioxidant additive or food dietary supplement.

Umbu Fruit Peel as Source of Antioxidant, Antimicrobial and α-Amylase Inhibitor Compounds

Herein, the extraction of bioactive compounds from umbu fruit peel was optimized using thermal-assisted solid–liquid extraction. In parallel, antioxidant, antimicrobial, and inhibitory effects against α-amylase of optimized extract were also evaluated. The combination of operational conditions including the temperature (32–74 °C), ethanol concentration (13–97%), and solid/liquid ratio (1:10–1:60; w/v) was employed using a rotational central composite design for optimization. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacity by ABTS•+, DPPH• and FRAP assays. The bioactive profile of the optimized extract was obtained by ultra-performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry in electrospray ionization in both negative and positive modes. The statistically evaluated results showed that the optimal operational conditions for the recovery of bioactive compounds from umbu fruit peel included 74 °C, 37% ethanol, and a solid–liquid ratio of 1:38. Under these conditions, the obtained values were 1985 mg GAE/100 g, 1364 mg RE/100 g, 122 µmol TE/g, 174 µmol/TE g and 468 µmol Fe2+/g for TPC, TFC, ABTS•+, DPPH•, and FRAP assays, respectively. In addition, the optimized extract was effective against Gram-positive and Gram-negative bacteria (MBC ranged from 0.060 to 0.24 mg GAE/mL), as well as it was effective to inhibit α-amylase (IC50 value of 0.076 mg GAE/mL). The optimized extract showed to be mainly constituted by phenolic acids and flavonoids.

Increasing levels of fibre and mineral (Fe, Ca, and K) in chicken meatballs added dragon fruit peel and oyster mushroom

The removal of the peel on dragon fruit fruits is a common step in food production for reasons of aesthetics and hygiene. One way to recycle dragon fruit peel is to make chicken meatball. Chicken meatball in Indonesia, which is called bakso are produced from ground chicken mixed with flour, spices and other mashed ingredients. The mixture is then formed into balls and boiled until cooked. Chicken meatballs contain mostly animal ingredients, so the quality needs to be improved by adding vegetable ingredients. The addition of vegetable ingredients is intended to increase the content of dietary fibre. The fruit fibres used in this study were dragon fruit peel and the vegetable ingredients was oyster mushrooms. The results showed that chicken meatball with higher concentration of dragon fruit peel has higher level of soluble dietary fibre, insoluble dietary fibre, and total dietary fibre content. This indicates that dragon fruit peel has higher levels of soluble dietary fibre, insoluble dietary fibre, and dietary fibre than oyster mushrooms. The addition of dragon fruit peel and oyster mushrooms causes an increase in iron and calcium mineral levels in chicken meatball products, but oyster mushrooms contribute more to increase these minerals. With these nutritious chicken meatballs, dragon fruit peel can be processed to become food that has economic value. Therefore, dragon fruit peel and oyster mushrooms can be used as a good ingredient in the formulation of chicken meatball.

ANTI-TYROSINASE AND ANTI-OXIDANT POTENTIAL OF METHANOLIC EXTRACTS OF SELECTED CITRUS BERGAMIA AND FICUS CARICA PARTS

Tyrosinase is a key enzyme in melanogenesis and its high activity leads to increasedpigmentations causing skin disorder like freckles, melanosoma and black spot. Therefore to search for new tyrosinase inhibitors is desirable. In present study, methanolic (MeOH) extracts from leaves, fruit peel and pulp of Citrus bergamia (CB) and, leaves and fruitof Ficus carica (FC) were prepared which were further process for fractional ethyl alcohol (EA), n-hexane (n-Hx) and chloroform (CHCl3)extractions (total 20 extracts) aiming to test their anti-tyrosinase potential, in-vitro. Our results confirmed that all MeOH FC and CB extracts showed significant anti-oxidant activity with IC50 range of 461.9 ± 16.1µg/ml to 2324.4 ± 116.1 µg/ml. Moreover, CB and FC all 20 extracts have significant anti-tyrosinase activity with IC50 range of 13.9 ± 0.5 µg/ml to 320.5 ± 3.3 µg/ml. Interestingly, CB MeOH-EA peel and leaf extracts showed tyrosinase inhibition (IC50) 13.9 ± 0.5 µg/ml and 17.2 ± 0.8 µg/ml, respectively) is better than all other tested extracts and positive control kojic acid (IC50=18.75±5.29µg/ml). Thus, CB MeOH-EA peel extract with lowest IC50 value among all the tested extracts and kojic acid is proposed as potent candidate to control tyrosinase rooted hyperpigmentation.