Quality Characteristics of Immature Citrus unshiu Juice Jelly

Abstract

This study investigated the effect of supplementation with immature Citrus unshiu juice (ICJ) on jelly quality characteristics. According to the amount of ICJ added, the ICJ jelly samples were divided into five groups, to determine differences in physicochemical properties: ICJ-0, ICJ-15, ICJ-30, ICJ-45, and ICJ-60 (immature Citrus unshiu jelly with 0, 15, 30, 45, and 60% ICJ, respectively). Konjac and κ-carrageenan were used as gelling agents, and all groups were gelled, regardless of the ICJ amount. Hunter b (yellowness) value of the jelly was increased with increasing ICJ supplementation, whereas the L (lightness) and a (redness) values were observed to decrease. Moreover, increasing amounts of ICJ resulted in increased levels of total phenolic content and total titratable acidity of the jelly, whereas the pH, moisture, and water activity (Aw) of the jelly were observed to decrease. The water holding capacity showed no significant difference among the groups (P>0.05). Texture properties for hardness and gumminess were significantly higher in the ICJ jellies (treatment group) than in the control (P<0.05). Depending on the ICJ amount, sensory properties of appearance, color, and taste of ICJ jelly were significantly different (P<0.05), but differences in texture and overall acceptability were not significant (P>0.05). Our results confirm that jelly prepared with 45% ICJ supplementation has the highest acceptability. Thus, we conclude that 45% ICJ is the optimal requirement for the preparation of high-quality jelly.

Metabolomic Profiling of Citrus unshiu during Different Stages of Fruit Development

“…Among these varieties, C. unshiu , commonly known as Satsuma mandarin, is an important easy-peeling mandarin and is widely cultivated throughout the main citrus production zones, including East Asia, Argentina, Australia, Peru, Spain, South Africa, and Uruguay [ 14 ]. In particular, C. unshiu —which is bud burst in middle of Mar., blooms in May, and is harvested after the middle of Nov. in East Asia [ 15 ]—is mostly consumed as a mature fruit, but the immature fruit is also consumed in various products, such as vinegar, jelly, and jams having strong antioxidant activity [ 16 , 17 , 18 ]. Although previous studies of C. unshiu have shown the changes in the phytochemical profiles of C. unshiu according to growing regions [ 19 ], post-harvest processes [ 20 ], and the comparison of the profiles with other citrus varieties [ 21 ], the changes in the phytochemical profile of C. unshiu during fruit development have not yet been analyzed.…”