Study On Syrup Used In Moon Cake

Sucrose invert syrup (SS) is on important material for making Guang style moon cake.Few literatures and researches were found about manufacturing of SS and its effect on qualityof moon cake. High fructose corn syrup (HFCS) has comparable constituents namely glucoseand fructose with SS. The present study is focusing on effect of SS on quality of moon cake,and HFCS substitutes for SS to make moon cake, the purpose is planning to make onealternative choice.Firstly, factors, such as addition content of water and citric acid, temperature, influencingconstituents of SS was researched and analyzed. Correlation analysis showed, fructose andglucose was positive with citric acid and water, negative with temperature. Sucrose wasreverse, negative with water and citric acid, positive with temperature. Adverse effect ofpineapple juice on inversion rate of sucrose was found and more than20percent of pineapplejuice was not favorable. Sucrose content of invert syrup had a fractional decline, and fructoseand glucose had a rise correspingingly within storing time. In contrast, content of fructose andglucose were falling when addition of pineapple juice, but not sucrose.Secondly, factors affecting color of moon cake were studied. Results were, discrepancywas not obvious within samples made by invert syrup boiled with different addition of citricacid. Significant changes of L*and a*value occurred with more alkaline water during secondbaking as compared with first baking. Samples made with SS boiled by addition of pineapplejuice had higher L*value, lower a*and b*value. Instead, lower L*, high a*, b*value werefound in the samples made with HFCS boiled with pineapple juice than samples made withHFCS. L*value was descended during storing time in four kinds of moon cake above, a*value was decreased in the SS samples but not others. b*value was increased in the samplesmade with HFCS and SS boiled with pineapple juice.Optimum composition of invert syrup for making moon cake, concentration80percent,fructose content was more than34.5percent and lower than41.7percent, the range of glucosewas between39.3percent and47.8percent, and scope of sucrose was from3.5percent to19.4percent, was get by quality and sensory scoring of moon cake and correlation analysis. For thesyrup boiled with pineapple juice, constituents would be concentration80percent, content offructose was more than35.5percent, glucose more than39.6percent and sucrose lower than19.0percent.Thirdly, maltose was not favorable for water migration but fat when addition was6percent base on invert ryrup. Maltodextrin with DE value20had higher water content but higher fat in the samples with DE value10. Samples of HFCS boiled with pineapple juice hadmore water content then HFCS samples, and holding fat addition of pineapple juice were10percent.0.20percent sodium citrate promoted water and fat migration when added in HFCS.Water and fat content were decreased when sucrose was added to HFCS.Syrup from HFCS should be boiled by addition of pineapple juice, for making mooncake with good quality. Its constituents were80percent concentration, fructose shouled bemore than37.7percent, glucose more than48.4percent and disaccharide lower than2.9percent.Lastly, volatile compounds of moon cakes were analyzed. And migration of water and fatwere analyzed by NMR imaging analysis. The main volatile compounds of SS sample wereHexanal, Limonene, Nonanal,(E,E)-2,4-Decadienal,(E)-2-Nonenal and2(5H) furanone.Three more compounds,2,3-Butanedione, trans-Geraniol and Decanal, was found in samplesafter addition of pineapple juice. Two more volatile compounds namely (E)-2-Octenal,trans-Geraniol in the HFCS samples compared with SS samples.2,3-Butanedione, Decanal,Octnal were three new volatile compounds found in HFCS samples added pineapple juice, butthe sample didn’t contain (E,E)-2,4-Decadienal and trans-Geraniol but its isomer, L-linalool.Further research of water and fat migration were taken by proton density imaging usingNMR. Protons in surface skin were increasing and decreasing in internal layers. Migration ofwater and oil was quickly in samples from HFCS compared with SS samples.