In vitro bioaccessibility and functional properties of polyphenols from pomegranate peels and pomegranate peels-enriched cookies

Abstract

Obesity is an urgent social problem and new functional foods providing polyphenols and dietary fibers (DF) may be promising tools to modulate oxidative stress, inflammation and energy homeostasis. Pomegranate peels (PPe) are an agro-industrial by-product containing polyphenols such as ellagitannins (ETs), gallic acid (GA), ellagic acid (EA) and its derivatives (EAs), as well as DF. In this study, PPe enriched cookies (PPeC) were developed, and the bioaccessibility as well as the ability of their polyphenols to exert antioxidant activity along the Gastro-intestinal Tract (GiT) and to modulate digestive enzymes were evaluated in vitro. Data showed that the potential bioaccessibility of ETs was 40% lower from PPeC than PPe whereas EAs' and GA bioaccessibility increased by 93% and 52% for PPeC compared to PPe. The concentration of the polyphenols at each digestion step was associated with the total antioxidant capacity of the potentially bioaccessible material. Moreover the polyphenols released in the simulated duodenal phase upon PPeC digestion exhibited inhibitory activity towards α-glucosidase, α-amylase and lipase, being α-glucosidase > α-amylase > lipase. In conclusion, the data demonstrated that the inclusion of PPe at 7.5% in a bakery product potentially led to a high bioaccessibility of ETs' degradation products (mainly EA and EAs) in the duodenum, with a consequent antioxidant protection along the GiT and modulation of glucose metabolism. Further human studies are warranted to evaluate whether these effects also occur in vivo.

Bioactive Compounds and Stability of a Typical Italian Bakery Products “Taralli” Enriched with Fermented Olive Paste

“…Various agri-food by-products rich in polyphenols, including pomegranate, mango, pigeon pea, and apple peels, have been mixed to the dough to prepare bakery products with functional properties. Some researchers reported that the supplementation of polyphenols in bakery foods could decrease starch digestibility and reduce the postprandial glucose levels in the serum, and is thus considered as alternatives to pharmaceutical interventions for the treatment of type II diabetes [25,26,27,28]. In this work, the addition of fermented OP to durum wheat flour led to a significant enrichment of polyphenol compounds.…”

Evaluation of microfiltration and heat treatment on the microbiological characteristics, phenolic composition and volatile compound profile of pomegranate (Punica granatum L.) juice

“…ETs ( α and β anomers of punicalin, punicalagin and pedunculagin), GA, EA and EAs (EA hexoside, EA pentoside, EA deoxyhexoside) were identified by liquid chromatography/tandem mass spectrometry (LC/MS/MS) and quantified by HPLC with diode array detection (HPLC‐DAD) according to Colantuono et al . Each sample was properly diluted in water/methanol (50:50 v/v) acidified with 5 mL L −1 formic acid.…”

“…Finally, 3.8 mL of bitartrate buffer solution in 120 mL L −1 ethanol (pH 3.6) was mixed with 100 µL of sample. The absorbance ( A ) at 520 nm was measured and the final value was multiplied by 20. The different forms of anthocyanins were expressed in absorbance units as …”

“…PJ is the major food product obtained from pomegranate arils, which constitute about 50% of the fruit weight and contain ∼78% juice and 22% seeds . Conversely, pomegranate peels are the most abundant by‐products resulting from pomegranate fruit industrial processing and can be extracted in order to obtain polyphenol‐rich extracts for cosmetic and nutraceutical applications or use as functional ingredients in the formulation of new foods …”

Inflammation and Oxidative Stress in an Obese State and the Protective Effects of Gallic Acid

“…Besides tea ( Camellia sinensis ), fruits that have been shown to contain high levels of gallic acid or its derivative compounds include avocado, ellagitannin-enriched polyphenolic extract, Eugenia dysenterica DC., freeze-dried jaboticaba peel, grape powder, herbal mixture, Limonium spp . (Plumbaginaceae), Mangifera indica L., mango, mulberry water, Nelumbo nucifera leaf, Norton grape pomace, number ten supplement, Ocimum basilicum , pineapple, pomegranate peels, Psidium guajava L., Pedro Sato, Paluma and Século XXI, Pu-erh tea, Punica granatum , Ribes nigrum L , Rubus suavissimus , and Terminalia bellirica [11,15,19,98,99,102,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,142,143,145].…”