摘要
试用各种物理、化学的方法处理批把果肉,研究控制批把果浆变褐的有效方法及各种化学试剂控制酶褐变的最适剂量.试验表明:微波处理批把果实1.5～2 min(60 g果实于200 ml介质溶液中),便能有效地钝化酚酶.如将果实置于0.1％Vc溶液或400 ppm亚硫酸氢钠溶液中微波处理,防褐效果更好,果浆色泽更稳定.低浓度(小于0.1％)柠檬酸烫漂防褐效果与沸水烫漂没有差异,烫漂时间 80～100 s即可钝化酶活性.用0.2％柠檬酸烫漂 60s,护色效果已较理想.当pH值低于3时,果浆护色效果最好;pH4.4～4.6时果浆褐变最严重.各种浓度的蔗糖溶液对酶促褐变并无明显的抑制作用.若抗坏血酸浓度为300～350ppm,Vc为400ppm时,亚硫酸氢钠200～250ppm,苯基硫脲37.5 ppm,二硫苏糖醇(DTT)50ppm,护色效果较稳定.铜试剂浓度为80ppm,硫脲60～70ppm,但其抑制作用均随时间的增加而减弱.护色效果最好的处理组合为:0.01％Vc,0.1％CaCl_2(W/V),pH2.0.
The research concerned with the physical and chemical ways of controlling the browning action of loquat
flesh (jelly). When the loquat fruits which were submerged in five different solutions were heated by mi-
crowaves, it showed that the PPO activity was inhibited within 60 to 120 seconds. The colour would be lighter
and more stable when the fruit were submerged in 0.1％(W/V) ascorbic acid solution or in 400 ppm sodium
hydrosulfite solution. Boiling treatments showed that the enzymes were inactivated in boiling water or
0.05％, 0.1％ citrate acid solutions (100℃)within 80 to 100 seconds. while in 0.2％ citrate acid solution, it
need only 60 seconds to reach the same result and had high colour stability. The pH treatment showed that
the L~* b~* /a~* value was very high when the pH in jelly was as low as 3.0. which meaned a very good light-
yellow colour. At pH 4.4 to 4.6 range, the jelly became heavy brown colour. Different concentration in jellies
as follows: ascorbic acid 300 to 350ppm sodium hydrosulfite 200 to 250 ppm: phenylthiourea 37.5 ppm; dithio-
threitol 50 ppm: sodium diethyl-dithiocat-bamate 80 ppm; thiourea 60 to 70 ppm. But all the jellies treated
with these chemicals would turn brown with the time. The study of combinative four treatments with two dif-
ferent concentrations, respectively, showed that the combination which reaches the best colour value was
0.01％(W/V) ascorbic acid, CaCl_2 0.1％, pH2.0.
出处
《科技通报》
1993年第3期176-181,共6页
Bulletin of Science and Technology
关键词
枇杷
果浆
褐变
色泽
抑制剂
loquat flesh
browning
heating
inhibitor
colour
