Six critical stages corresponding to major morphophysiological events in carob fruit ripening were defined, and changes in the primary and secondary metabolome and in vitro antioxidant capacity were examined in two genotypes collected at low (15 m) and high (510 m) altitudes from genetically identified and georeferenced trees. Soluble carbohydrates were analyzed by HPLC-RI, macro-minerals by ion chromatography coupled to conductivity detection and polyphenols by UHPLC-Q-Orbitrap-HRMS. spectroscopy facilitated assays for condensed tannins and in vitro free-radical scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP). The fruit respiration rate and moisture content declined sharply during the transition from the breaker to green pedicel stage. Sugar accumulation spiked at the onset of fruit coloration and culminated at 498.7 ± 8.4 mg g⁻¹ dry weight (dw) in the late ripe stage, while the ratio of reducing sugars to sucrose decreased from 3.45 ± 0.32 to 0.41 ± 0.02. The total phenolic compounds and condensed tannins declined with ripening, particularly during the transition from the breaker to green pedicel stage. Eighteen polyphenols were identified and quantitated, with catechins and hydrolyzable tannins being dominant until the onset of fruit coloration. The transition to the green pedicel stage signaled a precipitous decline (90.9%) in catechins, hydrolyzable tannins (60.2%) and flavonol glycosides (52.1%) concomitant to the rise in gallic acid, which was putatively fueled by the enzymatic hydrolysis of gallotannins in immature fruit. Catechins, hydrolyzable tannins and flavone glycosides were more abundant at higher altitudes and gallic acid at lower altitudes. An antioxidant capacity was also favored by higher elevations and declined with ripening, particularly after the breaker stage. Correlations with FRAP and DPPH assays were significant for the total phenolic content, condensed tannins, catechins and hydrolyzable tannins. The highest correlation factors were obtained for epigallocatechin-gallate (r = 0.920 and r = 0.900; p < 0.01). Although the sharp drop in hydrolyzable and nonhydrolyzable tannins and catechins compromised the in vitro antioxidant capacity at physiological maturity, it also reduced the astringency and configured a palatable organoleptic fruit profile. These changes unraveled significant episodes in the ripening-related secondary metabolism of the carob fruit. They further highlighted the value of immature carob as a potent source of gallotannins, with putative in vivo anti-inflammatory action, and of catechins beneficial in preventing and protecting against diseases caused by oxidative stress.

中文翻译：

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在成熟的关键阶段绘制角豆（Ceratonia siliqua L.）果实的主要和次要代谢组及其收获后的抗氧化潜力

定义了与角豆果实成熟过程中的主要形态生理事件相对应的六个关键阶段，并从遗传学鉴定的低（15 m）和高（510 m）高度收集了两种基因型，研究了初级和次级代谢组的变化以及体外抗氧化能力和地理参考树。通过HPLC-RI分析可溶的碳水化合物，通过离子色谱联用电导率检测分析大矿物，通过UHPLC-Q-Orbitrap-HRMS分析多酚。光谱法有助于测定单宁的缩合和1,1-二苯基-2-吡啶并二肼（DPPH）的体外自由基清除能力以及三价铁的抗氧化能力（FRAP）。从破碎机过渡到绿色花梗阶段，果实的呼吸速率和水分含量急剧下降。^-1成熟期后期的干重（dw），而还原糖与蔗糖的比例从3.45±0.32降低至0.41±0.02。酚类化合物和缩合单宁的总量随着成熟而下降，特别是在从破碎到绿色花梗阶段的过渡时期。鉴定并定量了18种多酚，其中儿茶素和可水解单宁占主导地位，直到果实着色开始。过渡到绿色花梗阶段表明，儿茶素，可水解单宁酸（60.2％）和黄酮糖苷（52.1％）与没食子酸上升同时急剧下降，这可能是由于没食子酸甘油酯的酶促水解所致未成熟的水果。儿茶素，可水解单宁和黄酮苷在较高的海拔高度丰富，没食子酸在较低的海拔高度。抗氧化剂的能力也受到较高海拔高度的青睐，并随着成熟而下降，特别是在破碎阶段之后。FRAP和DPPH分析的相关性对于总酚含量，缩合单宁，儿茶素和可水解单宁具有重要意义。表没食子儿茶素-没食子酸酯的相关系数最高（r = 0.920和r = 0.900；p <0.01）。尽管可水解和不可水解的单宁和儿茶素的急剧下降损害了生理成熟时的体外抗氧化能力，但它也降低了涩味，并构造了可口的感官水果味。这些变化揭示了豆角果实成熟相关的次级代谢中的重要事件。他们进一步强调了不成熟角豆树作为没食子鞣质的有效来源，具有推定的体内抗炎作用，以及儿茶素在预防和保护氧化应激疾病方面的价值。