Nutritional Profile, Phytochemical Compounds, Biological Activities, and Utilisation of Onion Peel for Food Applications: A Review

Abstract

The majority of the by products formed during onion processing remain unutilized, yet they are rich in bioactive compounds and phytochemicals. Onions are a very valuable vegetable. Onion chemical compounds are incredibly diverse, and they work through a variety of pharmacological mechanisms to prevent disease. Although the mechanism of the action of the chemicals found in onions has been studied, there is still room for further reformulating of nutrient supplements and pharmaceutical treatments thanks to a growing interest in sustainable resource utilisation and circular economy. This review focuses on the primary bioactive components found in onion peel and skin, particularly total phenolics, quercetin, total flavonoids, and their derivatives, as well as their therapeutic uses such as cardioprotective, anticancer, neuroprotective, antiobesity, antidiabetic, and antibacterial constituents. This review article noted that onion peel is a valuable agricultural byproduct that has a variety of biologically active compounds so it can be used as a health-regulating ingredient, particularly in the biomedical and pharmacological domains.

Food safety and quality. Scientific proceedings

“…Cibulové extrakty nebo sušený prášek mohou být přidávány jako funkční složka například do pšeničného a bezlepkového chleba, masových karbanátků nebo uzenin ze strojně odděleného rybího masa (Bedrníček et al, 2020). Manoj et al (2022) a Shabir et al (2022 prokázali, že kvercetin z cibulových slupek působí jako antimikrobiální činidlo tím, že narušuje energetický metabolismus a funkce cytoplazmatické membrány a inhibuje biosyntézu nukleových kyselin několika kmenům Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae a Staphylococcus pyogenes.…”

“…Běžný pokles pH ve svalu po porážce je z hodnoty pH 7,0 na pH 5,3-5,8, pro hovězí maso je obvykle pokles pH dokončen za 18-40 hodin od poražení zvířete (Savell et al, 2005). Dle Silva, et al (1999) lze hovězí maso podle finální hodnoty pH při zrání rozdělit na nezatížené vadou DFD (pH 5,5-5,8), středně zatížené vadou DFD (5,8<pH<6,2) a poškozené vadou DFD (pH 6,2-6,7).…”

Valorization of Fruit Waste for Bioactive Compounds and Their Applications in the Food Industry

“…Peels of Prunus cultivars, including the nectarine, apricot, and peach, are abundant in hydroxycinnamates and flavan-3-ols, which may have antioxidant properties [22]. Onion peel is reported to be rich source of flavonoids, including athocyanins, kaempferol, and quercetin derivatives (quercetin diglucoside, quercetin aglycone, and quercetin 4-O-glucoside) [23,24]. Phenolic compounds are secondary metabolites that are among the major classes of significant bioactive compounds with wide-ranging biological effects.…”

Extraction of microbial oil from Aspergillus niger and preparation of a sustainable growth medium for the same

“…Most of the agro waste management includes conversion of the crop residue to animal feed, but onion peels cannot be used for this purpose because of their strong aroma (Kumar et al, 2022). Considering the nature of onion peels as one of the habitats for Aspergillus niger and its unique composition of carbohydrates (88.56%) and nitrogen (15%) which can enhance lipid synthesis and storage in an oleaginous microbe (Shabir et al, 2022;Ochsenreither et al, 2016), we developed a growth medium from onion peels to culture A. niger.…”