大紅甜橙和冰糖橙果實發(fā)育過程中有機酸和氨基酸含量變化研究

孫系巍 龍桂友 李菲菲 盧曉鵬

摘 要：以冰糖橙和大紅甜橙為材料，研究兩個品種果實發(fā)育過程中有機酸和氨基酸含量的變化。結(jié)果表明，果實發(fā)育過程中大紅甜橙果實檸檬酸含量、總氨基酸含量均顯著高于冰糖橙；大紅甜橙和冰糖橙成熟果實中氨基酸總量分別為5.06 g/100g DW和3.46 g/100g DW，以天冬氨酸、谷氨酸和半胱氨酸含量較高。果實發(fā)育過程中，谷氨酸族氨基酸在大紅甜橙果實中無明顯變化，而在冰糖橙果實中逐漸降低；果實發(fā)育前期天冬氨酸族氨基酸含量在大紅甜橙果實中高于冰糖橙，而果實成熟期兩品種無明顯差異；鮮味和甜味氨基酸在大紅甜橙果實中含量均高于冰糖橙，且均伴隨果實成熟而降低。

關(guān)鍵詞：冰糖橙；大紅甜橙；有機酸；氨基酸

中圖分類號：S666.4 文獻標識碼：A 文章編號：1006-060X（2017）01-0026-04

Abstract：The aim of this work was to study the changes of organic acid and amino acid content in “Bingtangcheng” and “Dahongtiancheng” sweet oranges （Citrus sinensis）. The results showed that both citrate and amino acid in “Dahongtiancheng” was significantly higher than that in “Bingtangcheng” throughout fruit development. In ripening fruits， the total amino acid was 5.06 g/100g DW and 3.46 g/100g DW in “Dahongtiancheng” and “Bingtangcheng” respectively， in which Asp， Glu and Cys contributed to that difference significantly. During fruit development， glutamate families showed no significant change in “Dahongtiancheng” but decreased constantly in “Bingtangcheng”； aspartate families were higher in “Dahongtiancheng” than that in “Bingtangcheng”， but exhibited no difference at mature fruits； the flavor amino acids and sweet amino acids were higher in “Dahongtiancheng” than that in “Bingtangcheng”， and both of them decreased following fruits development.

Key words：Bingtangcheng； Dahongtiancheng； organic acid； amino acid

有機酸和氨基酸是柑橘果實的重要組成成分，其含量反映果實內(nèi)在品質(zhì)，直接影響柑橘果實的口感和被消費者的認可度。柑橘果實有機酸以檸檬酸為主，其來源是三羧酸循環(huán)的中間產(chǎn)物，其含量主要由檸檬酸的合成、降解和貯藏共同決定[1-4]。氨基酸是果實中主要的含氮化合物，但由于其在果實中含量較少，故在氨基酸參與果實品質(zhì)形成方面研究較少。研究表明，果實檸檬酸與氨基酸之間有密切的關(guān)系，如檸檬酸可轉(zhuǎn)化為谷氨酸，檸檬酸代謝的中間產(chǎn)物2-酮戊二酸參與多種氨基酸的形成等[5-7]。大紅甜橙和冰糖橙是兩個湖南省自主選育、推廣主栽的優(yōu)勢甜橙品種，均源于洪江普通甜橙的變異。……