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 巴西帕拉伊巴州博尔博雷马地区的家庭农场种植的甜橙供应区域市场。在此背景下，为提升产品附加值并打造更具竞争力的市场，亟需明确甜橙的身份标识与品质标准，并定量测定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析因完全随机试验设计，设置3个甜橙品种（巴伊亚（Baía）、普通（Comum）、米莫-杜-塞乌（Mimo-do-Céu））与3个成熟阶段（以绿色为主、绿黄相间、全黄）；物理性状检测每组设置60次重复，每次重复采用1个果实，其余检测项目每组设置4次重复，每次重复采用15个果实。针对完整果实，测定其色泽指数、果长、果径、鲜重及硬度。针对橙汁，测定其出汁率、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。在橙汁及果皮海绵层（albedo）中，检测了总提取多酚（Total Extractable Polyphenols，TEP），并采用ABTS•+与DPPH•两种自由基法测定总抗氧化活性。“巴伊亚”与“米莫-杜-塞乌”甜橙的品质参数符合CEAGESP标准。整体而言，供试甜橙的抗坏血酸含量均值高于45 mg·100g⁻¹，其中“米莫-杜-塞乌”的抗坏血酸含量最高，达50.26 mg·100g⁻¹。随着果实成熟度提升，果实硬度逐渐降低，而橙汁及果皮海绵层中的可溶性固形物、总提取多酚及总抗氧化活性均显著升高。总体而言，果皮海绵层中的总提取多酚含量约为橙汁的8倍，对应其总抗氧化活性也显著更高，由此凸显了该部分更高的功能开发价值，尤以“巴伊亚”甜橙为甚。