Screening and Characterization of Phenolic Compounds and Their Antioxidant Capacity in Different Fruit Peels

Fruit peels have a diverse range of phytochemicals including carotenoids, vitamins, dietary fibres, and phenolic compounds, some with remarkable antioxidant properties. Nevertheless, the comprehensive screening and characterization of the complex array of phenolic compounds in different fruit peels is limited. This study aimed to determine the polyphenol content and their antioxidant potential in twenty different fruit peel samples in an ethanolic extraction, including their comprehensive characterization and quantification using the LC-MS/MS and HPLC. The obtained results showed that the mango peel exhibited the highest phenolic content for TPC (27.51 ± 0.63 mg GAE/g) and TFC (1.75 ± 0.08 mg QE/g), while the TTC (9.01 ± 0.20 mg CE/g) was slightly higher in the avocado peel than mango peel (8.99 ± 0.13 mg CE/g). In terms of antioxidant potential, the grapefruit peel had the highest radical scavenging capacities for the DPPH (9.17 ± 0.19 mg AAE/g), ABTS (10.79 ± 0.56 mg AAE/g), ferric reducing capacity in FRAP (9.22 ± 0.25 mg AA/g), and total antioxidant capacity, TAC (8.77 ± 0.34 mg AAE/g) compared to other fruit peel samples. The application of LC-ESI-QTOF-MS/MS tentatively identified and characterized a total of 176 phenolics, including phenolic acids (49), flavonoids (86), lignans (11), stilbene (5) and other polyphenols (25) in all twenty peel samples. From HPLC-PDA quantification, the mango peel sample showed significantly higher phenolic content, particularly for phenolic acids (gallic acid, 14.5 ± 0.4 mg/g) and flavonoids (quercetin, 11.9 ± 0.4 mg/g), as compared to other fruit peel samples. These results highlight the importance of fruit peels as a potential source of polyphenols. This study provides supportive information for the utilization of different phenolic rich fruit peels as ingredients in food, feed, and nutraceutical products

A Dietary Sugarcane-Derived Polyphenol Mix Reduces the Negative Effects of Cyclic Heat Exposure on Growth Performance, Blood Gas Status, and Meat Quality in Broiler Chickens

Heat stress (HS) compromises growth performance and meat quality of broiler chickens by interrupting lipid and protein metabolism, resulting in increased oxidative damages. The experiment attempted to investigate whether dietary polyphenols (Polygain (POL)) could ameliorate the aforementioned adverse effects of HS on performance and meat quality. One hundred and twenty one day-old-male chicks were allocated to two temperature conditions, thermoneutral (TN) or HS, and fed with either a control diet (CON) or the CON plus four different doses of POL (2, 4, 6 and 10 g/kg). Heat stress caused respiratory alkalosis as evidenced by increased rectal temperature (p < 0.001) and respiration rate (p < 0.001) due to increased blood pH (p < 0.001). Heat stress decreased final body weight (p = 0.061) and breast muscle water content (p = 0.013) while POL improved both (p = 0.002 and p = 0.003, respectively). Heat stress amplified muscle damages, indicated by increased thiobarbituric acid reactive substances (p < 0.001) and reduced myofibril fragmentation index (p = 0.006) whereas POL improved both (p = 0.037 and p = 0.092, respectively). Heat stress impaired meat tenderness (p < 0.001) while POL improved it (p = 0.003). In conclusion, HS impaired growth performance and meat quality whereas POL ameliorated these responses in a dose-dependent manner, and effects of POL were evident under both temperature conditions

Ethnic and paleolithic diet: where do they stand in inflammation alleviation? A discussion

The current food options, especially in the Western countries, are acidogenic, which reduce extracellular pH and perturb ionic homeostasis. The acidity-activated enzymes mediate a large panel of chronic and acute diseases. To quell the morbidities and mortalities associated with the metabolic syndromes, nonpharmacologic approaches are preferred. Dietary interventions are critical in this regard. Among the array of dietary patterns, paleo diet has garnered much attention in the last decade. This diet rich in phytochemicals and unsaturated fatty acids is deemed wholesome for the body. Several studies have proven this claim, yet their nutritional adequacy for all age groups is contentious. The popularity of ethnic foods is rising; but their nutrition and safety position can vary. Although some of them are close to paleo food, some are unhealthy. This review explores the mechanism by which paleo diet restores homeostasis of the body and how its inherent nutritional deficiency can be amended with conventional diet, by the formulation of personalized diet. This compilation is expected to be insightful for dietary optimization

Therapeutic Potential of Seaweed Bioactive Compounds

Edible seaweeds are rich in bioactive compounds such as soluble dietary fibers, proteins, peptides, minerals, vitamins, polyunsaturated fatty acids and antioxidants. Previously, seaweeds were only used as gelling and thickening agents in the food or pharmaceutical industries, recent researches have revealed their potential as complementary medicine. The red, brown and green seaweeds have been shown to have therapeutic properties for health and disease management, such as anticancer, antiobesity, antidiabetic, antihypertensive, antihyperlipidemic, antioxidant, anticoagulant, anti-inflammatory, immunomodulatory, antiestrogenic, thyroid stimulating, neuroprotective, antiviral, antifungal, antibacterial and tissue healing properties. In proposed chapter, we discussed various active compounds include sulphated polysaccharides, phlorotannins, carotenoids (e.g. fucoxanthin), minerals, peptides and sulfolipids, with proven benefits against degenerative metabolic diseases. Moreover, therapeutic modes of action of these bioactive components and their reports are summarized in this chapter

Evaluation of legumes for fermentability and protein fractions using in vitro rumen fermentation

Diversifying feed with non-traditional options could minimize the dependency on traditional sources, maintain the feed supply throughout the year, and potentially reduce the cost of raising animals. A total of eight forage legumes including Peltophorum pterocarpum, Neptunia monosperma, Vachellia sutherlandii (Corkwood), Gliricidia sepium, Bauhinia hookeri and three Desmanthus species (JCU4, JCU5 and JCU9) were collected to assess their in vitro fermentability, degradable and undegradable protein fractions using in vitro gas production method. Soybean meal and lucerne hay were used as control. The total gas production ranged from 12.8 mL/g in P. pterocarpum to 127.3 mL/g in soybean meal. The total volatile fatty acid (VFA) concentration from G. sepium (117.7 mM/L) and V. sutherlandii (111.3 mM/L) were larger than other legumes except for soybean meal (157.1 mM/L) and lucerne hay (130.4 mM/L), P < 0.001. The methane gas produced from B. hookeri and P. pterocarpum (0.39 and 0.32 mL/g) was lower than other feeds, P < 0.001. The V. sutherlandii (720 g/kg crude protein (CP)) and G. sepium (745 g/kg CP) had the greatest effective CP degradation (EPD) than other legume species examined, P < 0.001, which was approaching that measured in the control samples. The amount of protein fraction ‘a’ (rapidly degradable) was larger in JCU9 (551 g/kg CP), and G. sepium (472 g/kg CP), and lower in B. hookeri (10.9 g/kg CP) and P. pterocarpum (14.8 g/kg CP), P < 0.001. The V. sutherlandii (386 g/kg CP) and G. sepium (272 g/kg CP) exceeded other legumes in the proportion of fraction ‘b’ (slowly degradable), P < 0.001, but not the controls. The undegradable fraction increased with increasing phenolic content and reached more than 940 g/kg CP for both B. hookeri and P. pterocarpum. The Desmanthus cultivars showed intermediate values among the tested legumes in fermentation characteristics and shows potential to provide slowly degradable protein while reducing methane. The findings indicate the possibility of using V. sutherlandii and G. sepium to substitute other forages for their greater slowly degradable protein content. Moreover, B. hookeri and P. pterocarpum plants emerged as candidates to assist protein protection in the rumen and reduce methane emissions. However, these legumes need to be evaluated in vivo before promoting for further use to confirm the variability reported here

A Comparative Investigation on Phenolic Composition, Characterization and Antioxidant Potentials of Five Different Australian Grown Pear Varieties

Pear (Pyrus communis L.) is widely spread throughout the temperate regions of the world, such as China, America and Australia. This fruit is popular among consumers due to its excellent taste and perceived health benefits. Various bioactive compounds, which contribute to these health benefits, have been detected in the pear fruits, including a range of phenolic compounds. Five Australian grown pear varieties, which include Packham’s Triumph, Josephine de Malines, Beurre Bosc, Winter Nelis and Rico were selected for this study to examine the phenolic compounds in pears. Beurre Bosc exhibited the highest total polyphenol content (TPC) (3.14 ± 0.02 mg GAE/g), total tannin content (TTC) (1.43 ± 0.04 mg CE/g) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) (5.72 ± 0.11 mg AAE/g), while the Josephine de Malines variety was high in total flavonoid content (TFC) (1.53 ± 0.09 mg QE/g), ferric reducing antioxidant power (FRAP) (4.37 ± 0.04 mg AAE/g), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (4.44 ± 0.01 mg AAE/g) and total antioxidant capacity (TAC) (5.29 ± 0.09 mg AAE/g). The liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) data indicate that a total of 73 phenolic compounds were detected in Beurre Bosc (37 compounds), Josephine de Malines (34), Rico (22), Packham’s Triumph (15) and Winter Nelis (9), respectively. From HPLC-PDA quantification, the Beurre Bosc pear variety showed significantly higher in phenolic acids (chlorogenic acid; 17.58 ± 0.88 mg/g) and while flavonoids were significantly higher in Josephine de Malines (catechin; 17.45 ± 1.39 mg/g), as compared to other pear varieties. The analyses suggest that the Australian grown pears might contain an ideal source of phenolic compounds which benefit human health. The information provided by the present work can serve as practical supporting data for the use of pears in the nutraceutical, pharmaceutical and food industries

Identification and characterization of rhizospheric microbial diversity by 16S ribosomal RNA gene sequencing

In the present study, samples of rhizosphere and root nodules were collected from different areas of Pakistan to isolate plant growth promoting rhizobacteria. Identification of bacterial isolates was made by 16S rRNA gene sequence analysis and taxonomical confirmation on EzTaxon Server. The identified bacterial strains were belonged to 5 genera i.e. Ensifer, Bacillus, Pseudomona, Leclercia and Rhizobium. Phylogenetic analysis inferred from 16S rRNA gene sequences showed the evolutionary relationship of bacterial strains with the respective genera. Based on phylogenetic analysis, some candidate novel species were also identified. The bacterial strains were also characterized for morphological, physiological, biochemical tests and glucose dehydrogenase (gdh) gene that involved in the phosphate solublization using cofactor pyrroloquinolone quinone (PQQ). Seven rhizoshperic and 3 root nodulating stains are positive for gdh gene. Furthermore, this study confirms a novel association between microbes and their hosts like field grown crops, leguminous and non-leguminous plants. It was concluded that a diverse group of bacterial population exist in the rhizosphere and root nodules that might be useful in evaluating the mechanisms behind plant microbial interactions and strains QAU-63 and QAU-68 have sequence similarity of 97 and 95% which might be declared as novel after further taxonomic characterization

Effects of postharvest processing on aroma formation in roasted coffee – a review

Postharvest processing of coffee cherries significantly influences sensory characteristics and commercial values. Aroma is one of the critical elements in product qualification and differentiation of coffees from different origins, roasting levels and brewing methods. Except for primary coffee volatile organic compounds (VOCs) (furans and pyrazines), which are generated during postharvest processing (dry, honey, wet processing and roasting), aldehydes, ketones, phenols, sulphur compounds and others could also contribute to the complex coffee flavour. Desirable flavour requires a balance between pleasant and defective VOCs. This review comprehensively discussed the mechanisms of conventional and novel postharvest processing of coffee beans, their impact on the sensorial profile of green and roasted coffee, and the composition, generation and analysis techniques of coffee VOCs. This review shows the feasibility of GC–MS and electronic nose (E-nose) in coffee VOCs and flavour detection, meanwhile building a comprehensive linkage between postharvest processing and coffee sensory characteristics

High-Throughput Screening and Characterization of Phenolic Compounds in Stone Fruits Waste by LC-ESI-QTOF-MS/MS and Their Potential Antioxidant Activities

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries