QUALITY, BIOACTIVE COMPOUNDS AND ANTIOXIDANT ACTIVITY DURING MATURATION OF ORANGES PRODUCED IN THE BORBOREMA TERRITORY

ABSTRACT The family farming from the Borborema Territory-PB, Brazil, produces sweet oranges that supply the regional market. In this context, it is necessary to define standards of identity and quality, as well as to quantify the bioactive compounds in the fruit, in view of adding value and creating more competitive markets. This work sought to evaluate the quality, bioactive compounds and total antioxidant activity (TAA) of oranges from family farming. A 3x3 factorial completely randomized design was used, with three cultivars (Baía, Comum, Mimo-do-Céu) and three maturity stages (predominantly green, green/yellow, yellow), with 60 replications of 1 fruit for the physical evaluations, and 4 of 15 fruit for the others. The whole fruits were evaluated by color index, length, diameter, fresh weight and firmness. The juice was assessed for yield, pH, soluble solids (SS), titratable acidity (TA), SS/AT ratio, and ascorbic acid. Total extractable polyphenols (TEP) and ABTS•+ and DPPH• total antioxidant activity (TAA) were measured in the juice and albedo. The 'Baía' and 'Mimo-do-Céu' oranges presented quality parameters aligned with the CEAGESP standards. On average, the ascorbic acid content was higher than 45 mg 100 g-1, with ‘Mimo-do-Céu’ presenting the highest content (50.26 mg 100 g-1). During maturation, the firmness decreased, and the SS, TEP and TAA of the juice and the albedo increased. In general, the TEP content was about eight-fold higher in the albedo than juice, corresponding to the much higher TAA in this portion, thereby highlighting its higher functional potential, especially for ‘Baía’ orange.

摘要 巴西博尔博雷马领地-帕拉伊巴州（Borborema Territory-PB）的家庭农场生产的甜橙供应区域市场。在此背景下，为实现产品增值并打造更具竞争力的市场，亟需明确其身份标识与品质标准，并量化果实中的生物活性成分。本研究旨在评估家庭农场种植甜橙的品质、生物活性成分及总抗氧化活性（Total Antioxidant Activity, TAA）。本研究采用3×3因子完全随机设计，设置3个品种（Baía、Comum、Mimo-do-Céu）与3个成熟阶段（以绿色为主、绿黄相间、纯黄色）；其中物理品质评价每组设置60次重复，每次重复为1颗果实，其余指标每组设置4次重复，每次重复为15颗果实。对完整果实测定色泽指数、果长、果径、鲜重及硬度；对果汁检测出汁率、pH值、可溶性固形物（Soluble Solids, SS）、可滴定酸度（Titratable Acidity, TA）、SS/AT比值及抗坏血酸含量。分别对果汁与白皮层（albedo）的总可提取多酚（Total Extractable Polyphenols, TEP），以及ABTS•+、DPPH•体系下的总抗氧化活性（TAA）进行测定。研究结果显示，‘Baía’与‘Mimo-do-Céu’甜橙的品质参数符合CEAGESP标准。平均而言，供试样品的抗坏血酸含量高于45 mg·100g⁻¹，其中‘Mimo-do-Céu’的含量最高，达50.26 mg·100g⁻¹。随着成熟度提升，果实硬度下降，而果汁与白皮层中的可溶性固形物、总可提取多酚及总抗氧化活性均显著上升。总体而言，白皮层中的总可提取多酚含量约为果汁的8倍，对应其总抗氧化活性也显著更高，凸显出该部位更高的功能潜力，尤以‘Baía’甜橙最为突出。