NUTRITIONAL CHARACTERIZATION AND THE ANTIOXIDANT PROPERTIES OF SWEET ORANGE AND RED GRAPEFRUIT PEELS

P.Al. Vlaicu, Tatiana Dumitra Panaite, Arabela Elena Untea, Mihaela Saracila, Olteanu Margareta

Abstract
   Sweet oranges (Citrus sinensis) and red grapefruit (Citrus paradisi) are fruits consumed frequently in the world, being part of the human diet for decades due to high nutritional and medicinal values. These are excellent sources of vitamin C, a powerful natural antioxidant that builds the body's immune system. Their consumption (natural or processed) generates more quantities of shells and wastes that cause pollution of the environment under incorrect handling conditions. The study was conducted to analyze the potential of orange and grapefruit peels, from a chemical point of view, to determine the nutritional value for inclusion in broiler feed. The orange peels were characterized by a 5.42% crude protein and 1.04% crude fat vs. 5.78% and 0.80% grapefruit. The total content of polyphenols (mg acid galic /g) determined was higher with 36.01% in grapefruit peels compared to those of oranges. Antioxidant capacity was determined by two in vitro methods. The grapefruit peels were characterized by a high antioxidant capacity (288.49 mmol /kg equivalent ascorbic acid) with 51.39% higher than the values of the orange peels, in the first method. For the second method, the determined antioxidant capacity was with 61.20% higher than the orange peels (95.46 mmol/ kg equivalent vitamin E). Based on these results, the analyzed by-products fulfill the necessary conditions to be integrated into the animal feed, and they will be tested in an experiment on broiler chickens in order to improve the nutritional quality of the meat.

CARACTERIZAREA NUTRIŢIONALĂ ŞI PROPRIETĂŢILE ANTIOXIDANTE ALE COJILOR DE PORTOCALE DULCI ŞI GRAPEFRUIT ROŞU

P.Al. Vlaicu, Tatiana Dumitra Panaite, Arabela Elena Untea, Mihaela Saracila, Olteanu Margareta

Rezumat
    Portocalele dulci (Citrus sinensis (L.)) si grapefruitul roşu (Citrus paradisi) sunt fructe consumate frecvent în lume, făcând parte din dieta umană de decenii datorită valorilor nutritive şi medicinale ridicate. Acestea, reprezintă surse excelente de vitamina C, puternic antioxidant natural care construieşte sistemul imunitar al organismului. Consumul lor (natural sau procesat) generează cantităţi mai de coji si deşeuri care provoca poluarea mediului in condiţii de manipulare incorecta. Studiul s-a realizat pentru a analiza potenţialul cojilor de portocala si grapefruit, din punct de vedere chimic pentru a determina valoarea nutriţională in vederea includerii lor in hrana broilerilor. Cojile de portocale s-au caracterizat printr-o proteina de 5.42% si grasime 1.04% vs.5.78% si 0.80% grapefruit. Conţinutul total de polifenoli (mg echiv ac.galic/g) determinat, a fost cu 36.01% mai mare in cojile de grapefruit comparativ cu cele de portocale. Capacitatea antioxidanta a fost determinata prin doua metode in vitro. Cojile de grapefruit s-au caracterizat printr-o capacitate antioxidanta ridicata (288.59 mmoli/kg echiv ac. ascorbic) cu 51.39% mai mare fata de valorile cojilor de portocale, in cazul primei metode. Pentru a doua metoda, capacitatea antioxidanta determinata a fost cu 61.20% mai mare fata de cojile de portocale (95.46 mmoli/kg echiv vit.E). Pe baza acestor rezultate, subprodusele analizate îndeplinesc condiţiile necesare pentru a fi integrate in hrana animalelor.

Cuvinte cheie: citrice; coji de portocala; grapefruit; caracterizarea nutritionala; proprietati antioxidante