鲜食甜玉米甜酒酿罐装食品的工艺研究

对鲜食甜玉米甜酒酿罐装食品的发酵工艺和罐装食品内容物的配比进行试验研究.试验结果表明:鲜食甜玉米甜酒酿发酵的最佳工艺条件为:甜酒曲用量1.0%、发酵温度25℃、发酵时间4d、料液比1:0.8;鲜食甜玉米甜酒酿罐装食品内容物最佳配比为:甜酒醪与水的比例为1:2,加糖量8%.产品可溶性固形物为8.5%,酒精度≤1.5°.     

新型糯玉米甜酒酿的酿制工艺

以优质糯玉米为原料,采用固态开放式发酵工艺酿制甜酒酿。通过正交试验确定糯玉米甜酒酿的最佳发酵工艺参数:糯玉米碴粒度2.7 mm,甜酒曲用量1.5%,蔗糖添加量4%,发酵时间72 h。同时确定出甜酒酿产品的最佳糖酸比:37∶1。     

糯米、甜荞混合甜酒酿发酵工艺的研究

以糯米和甜荞为原料,采用安琪甜酒曲作为发酵酒曲制作甜酒酿。通过单因素试验对糯米与甜荞质量比、甜酒曲添加量、发酵时间以及发酵温度进行研究,在单因素试验的基础上进行正交实验,以感官指标作为评价标准以确定酒酿的最佳工艺条件,实验结果表明,糯米与甜荞质量比为4∶1,酒曲添加量1.0%,发酵时间72h,发酵温度25℃,按此最佳条件制作的甜酒酿风味独特。     

发芽糙米和糯米甜酒酿的研制

以发芽糙米和糯米为原料,经安琪甜酒曲发酵制成混合甜酒酿。通过单因素试验和正交试验探讨甜酒酿的研制工艺,得出最佳工艺:在31℃的条件下,将发芽糙米和糯米混合发酵55 h,安琪甜酒曲的添加量为0.35%,蒸饭时间为38 min,糙米与糯米的质量比为1∶3。这是在传统糯米甜酒酿基础上的进一步创新。混合发酵后的甜酒酿有发芽糙米独特的香气,并且增强了其营养价值。     

小米苦荞米酒加工工艺优化

以糯米、小米和苦荞为主要原料,采用甜酒曲作为发酵剂,通过单因素试验及正交试验对原料配比、发酵条件进行优化,并对所得成品的感官指标、理化指标及抗氧化活性进行测定。结果表明,小米苦荞米酒的最佳配比：糯米∶小米∶苦荞质量比为6∶3∶2;最佳发酵条件：酒曲添加量为0.4%,料液比为20∶6（g/mL）,发酵时间为96 h。最优工艺条件下制得的小米苦荞米酒营养丰富,口感醇厚,香气宜人,且具有一定的抗氧化功能。     

甜酒酿的发酵工艺及其稳定性研究

以糯米为原料,经浸泡、蒸饭、拌曲、糖化和发酵等工序,得到醇甜清爽、风味和营养具佳的糯米甜酒;通过L9(34)正交试验确定甜酒酿发酵最佳工艺参数:拌曲量0.2％、发酵温度30℃、发酵时间60h、并对糯米甜酒主要指标的稳定性进行了研究.     

葛根糯米混合甜酒酿发酵工艺研究

以荆门地区葛根、糯米为原料,接种甜酒曲进行混合甜酒酿发酵。选取葛根与糯米的比例、酒曲接种量、发酵温度、发酵时间为条件,采用单因素试验和正交试验对混合甜酒酿的发酵工艺进行优化。结果表明,最佳发酵工艺为葛根与糯米质量比为1.0∶1.5、酒曲接种量为2.0%、发酵温度为30 ℃,发酵时间为3 d,在此条件下,制得的甜酒酿感官评分为85分,总糖含量为35.4%,酒精度为3.3%vol,黄酮含量为4.2 mg/100 mL,总酸含量为82.3 mg/100 mL（以柠檬酸计）。     

新型桂花米酒的酿造工艺研究

以桂花、糯米为主要原料,以残糖和产品的感官性状为指标,对影响其品质的5个因素(发酵剂、发酵剂用量、主发酵温度、料液比和桂花用量)进行考察,选择3个主要因素(发酵剂用量、主发酵温度和料液比)作正交试验,确定其工艺条件.结果表明,最佳工艺条件为:以安琪甜酒曲作为发酵剂、发酵剂用量为0.4％、主发酵温度28℃、料液比1∶1、桂花用量2％.所得桂花糯米酒清亮,酒香浓郁,入口清甜爽口,桂花香淡雅.     

黑米醪糟酒工艺条件的探讨

以黑米和糯米为主料,甜酒曲和白糖为辅料,半固态发酵工艺酿制黑米醪糟酒.通过单因素试验优选出黑米醪糟酒的最佳发酵工艺条件,即黑米与糯米添加比1.4:1,甜酒曲添加量1%,加糖量10%,发酵时间36h,发酵温度35℃,蒸煮时间55min,蒸20min,煮35min,料水比1:3,酿制出的黑米醪糟酒呈紫红色,半透明,有光泽,香气纯正,馥郁芬芳,幽雅自然,滋味醇厚,甜酸柔和,鲜美爽口,测得其pH5.4,糖度6.7%.     

益生菌甜酒酿的研究

以糯米经甜酒曲糖化发酵后的醪液(甜酒酿)为初始培养基,通过在其中添加各种促生长因子,对益生菌嗜酸乳杆菌的最适生长培养基及培养条件进行了研究。结果表明,在12Bx糖度的甜酒酿中加入0.1%的大豆蛋白胨和1.5%的脱脂奶粉后培养嗜酸乳杆菌,在37℃下恒温培养16～18h,其活菌数可达5.8×108cfu/ml,酸度可控制在0.5%以下。     

FLAVOR AND TEXTURE OF PRESERVED INTACT SWEET CORN: COMPARISON WITH CUT SWEET CORN AND STORAGE TESTS

Sensory studies were conducted to determine if intact or unit kernels of sweet corn (i.e. kernels which are detached at their normal abscission layer and lack a cut surface) can replace cut kernels. Samples of intact or unit kernel sweet corn were compared hedonic-ally and by relative preference with samples of cut sweet corn after appropriate processing. Stability of the frozen and canned intact kernels was studied for one year. Hedonic ratings for frozen intact corn yielded values of 7.4–7.6 and compared to values of 6.0–6.2 for cut corn. Hedonic ratings for canned intact corn yielded values from 6.4–6.8 and compared to values of 5.9–6.1 for cut corn. Laboratory taste panels expressed preference for intact samples in 86–89s of the judgements of frozen corn and in 64–86s of the judgements of canned corn. Both flavor and texture of the intact corn were most frequently cited as the reasons for preference. Frozen samples of intact kernels were stable for at least 1 yr at ?18°C. Canned samples of intact kernels of Golden Jubilee and Golden Happiness were stable for 1 yr at 18°C. Sensory differences were detected in Stylepak samples at the 12-month evaluation.     

MODIFIED ATMOSPHERE PACKAGING of SWEET CORN ON COB

Respiration rates (RR) of two varieties of sweet corn on cob were determined at O₂ concentrations: 5, 10, 15, and 21% and CO₂: 0, 5, and 10%, and temperatures: 2, 12, and 25C. Temperature and O₂ had strong influence on RR. Activation energies for effect of temperature on RR(O₂) and RR(CO₂) were, 44.6 and 104.4 kJ/mole, respectively. At 12C, to maintain 4% O₂ and 6% CO₂ in a package 10.8 cm² area, with 1.12 kg of corn, the estimated film permeabilities were 14 ml O₂/h.cm² and 65 ml CO₂/h.cm², respectively. Experimental and theoretical transient gas concentrations using microporous films were in reasonable agreement, but the desired O₂ and CO₂ levels were not achieved.     

PARTIAL PURIFICATION AND CHARACTERIZATION OF SWEET CORN GERM LIPOXYGENASE

Lipoxygenase (LPO) extracted from the germ fraction of sweet corn (Zea mays L. var. Jubilee) was purified by acetone powder preparation; extraction with 0.1 M Tris-HCl, pH 8; 40–60% fractionation with ammonium sulfate; and conventional column chromatography on Sephacryl S-300 HR and Fast Protein Liquid Chromatography (FPLC) on a Mono Q column. A 124-fold purification was achieved with 26.3% recovery. Further purification was achieved by FPLC chromatofocusing on a Mono P column and size exclusion chromatography on Superose-12, with a resultant 436-fold purification and 16.8% recovery. The apparent molecular weight and isoelectric point (pI) determined by FPLC on Superose-12 and Mono P columns were 90,500 and 5.06, respectively. Lipoxygenase-catalyzed formation of conjugated dienes was inhibited by both synthetic (BHA, BHT) and natural phenolic antioxidants (quercetin, chlorogenic acid) at a concentration of 0.2 mM with 57.2, 16.3, 61.4 and 32.3% inhibition, respectively. The activation energy for thermal inactivation of sweet corn germ lipoxygenase from the ammonium sulfate preparation at 55–70C was 56.3 kcal/mol.     

CLASIFICATION OF SWEET CORN AROMAS BY STEPWISE DISCRIMINANT ANALYSIS

Cooked sweet corn aroma volatiles were analyzed by gas chromatography using a headspace technique. Aroma profiles of corn from early and late plantings, different stages of maturity, different cultivars, and different processes were submitted to stepwise discriminant analysis (BMD-0–7M). Processes were most often classified correctly with slight overlaps between brine-pack canned cron and vacuum-packed canned corn and more notable overlapping between frozen and vaccum frozen corn. Corn from different plantings were classified correctly about two-thirds of the time on the basis of their aroma profiles. Stylepak and NK199 cultivars were most often classified correcltly; similarities expressed in overlapping classifications were apparent among Butersweet, Silver Queen NK199 and among code 556, Buttersweet and Silver Queen. Fancy grade corn was correctly classified about 45% of the time, extra standard about 67% of the time, and standard about 68% of the time. By strafifying the data by processing method prior to discriminant analysis, improved classification was achieved for cultivars and maturities.     

DISTRIBUTION AND HEAT INACTIVATION OF PEROXIDASE ISOENZYMES IN SWEET CORN

The distribution and heat inactivation of peroxidase (EC 1.11.1.7) isoenzymes in the pericarp, germ and endosperm of three sweet-corn ( Zea mays ) hybrids (Hawaiian hybrid H68, high-lysine hybrid o₂su COMP 1c, and a high-sucrose hybrid sh2 SYN 2e) were investigated. Polyacrylamide gel electrophoresis showed that the isoenzyme content of all three tissue fractions were complex with the pericarp having the largest number of isoenzymes. Isoenzyme distributions in the three varieties were similar but with exceptions, the most notable being the relatively simple distribution in the endosperm of H68. Studies on relative heat stabilities of the peroxidase isoenzymes at 71°C showed that no fraction was completely heat resistant although most bands did contain some heat resistant forms. Only one isoenzyme fraction, which was present in all three varieties, was completely heat labile. In contrast, some isoenzyme bands in the germ and endosperm were completely heat labile in some varieties but not in others. These results suggest that heat inactivation and consequently, residual peroxidatic activity found in processed corn is determined not only by isoenzyme content but also by the variable heat resistance of some isoenzyme fractions.     

MODIFIED VISCOMETRIC METHOD FOR THE EVALUATION OF SWEET CORN MATURITY

A modified viscometric method was developed for evaluating sweet corn maturity. The optimal deformation (shear) rate of the test was found to be 48.6 s^-1. A simple power-law flow model was applied. Apparent viscosity correlated highly with maturity parameters. Freezing increased the viscosity of the corn slurries. Apparent viscosity and Back Extrusion maximum force were satisfactory indexes of quality for frozen corn.