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.     

Effect of hydro co-extrusion on microstructure of duo-cast Al 3003/Al 4004 clad materials

The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.