Development and evaluation of deep-fried, frozen sweet potato rounds

Objectives of this study were twofold: (a) development of a new form of sweet potato product referred to as sweet potato rounds? and (b) evaluation of samples for quality attributes including sensory, chemical, physical, and caloric content. Sensory panels consisting of 15 university staff and students of food-oriented departments showed some preference for samples prepared in each of the three methods of final preparation: microwave heating, conventional heating and deep-frying. However, samples finished by deep frying were most preferred and samples finished in a microwave oven were least preferred. Proximate composition showed that deep-fried samples had the highest amount of absorbed oil; consequently, these samples contained the highest caloric content when compared to the samples finished in a microwave or conventional oven and deep-fried commercially prepared white potato rounds. Hunter color measurements showed that deep-fried samples were lightest and retained most of their characteristic orange-yellow color. Conventionally-heated and microwave-heated samples were darker and lost some of their natural orange-yellow color. However, small differences existed between samples finished in the two types of ovens. Instron firmness values showed that conventionally-heated samples were firmer than the microwave-heated samples. No comparison was made between samples that were deep-fried or finished by heating in the ovens. However, absolute values showed that deep-fried samples had comparable firmness values as those of conventionally-heated samples. This study shows that acceptable sweet potato rounds can be prepared either by conventional methods using a conventional oven and a deep fryer or by a more convenient but least preferred method using a microwave oven

Determination of sodium fatty acid in soap Formulation Using Fourier Transform Infrared (FTIR) spectroscopy and multivariate calibrations.

Fourier Transform Infrared (FTIR) spectroscopy using an attenuated total reflectance (ATR) accessory has been investigated as a method for the determination of sodium-fatty acid (sodium-FA) in soap formulations. Multivariate calibrations namely partial least squares regression (PLS) and principle component regression (PCR) were developed for the prediction of sodium-FA using spectral ranges on the basis of relevant IR absorption bands related to sodium-FA. The sodium-FA content in soap formulations was predicted accurately at wavenumbers of 1,570–1,550 cm−1, which is specific for RCOO− Na+ vibration. The PLS method was found to be a consistently better predictor when both PLS and principal component regression (PCR) analyses were used for quantification of sodium-FA. Furthermore, FTIR spectroscopy can be an alternative technique to American oil Chemist Society methods which use a titrimetric technique because FTIR offers rapid, easy sample preparation and is friendly to the environment

Acid Inactivation of Soybean Lipoxygenase and Its Effects on Protein Solubility

227 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.This study investigated a method of inactivating soybean lipoxygenase while minimizing protein insolubilization with various acids at low pH without heating. The effects of acid on trypsin inhibitor and urease activities in the products were also studied.Sensory scores of 10% neutralized soy slurries prepared by direct acid grinding to pH 3.0-3.8 and slurries from beans soaked for 8 hours in 0.15 M HCl showed no significant difference (P > 0.05) from the blanched lipoxygenase-free control. By the chemical assay, lipoxygenase was found to be irreversibly inactivated during acid grinding at about pH 3.0. Electrophoretic pattern of SDS-polyacrylamide gel showed the band corresponding to lipoxygenase was absent from the samples treated at pH 3.0 and below. In acid soaking, the time needed to inactivate lipoxygenase decreased with increasing acid concentration and higher soaking temperature.Full-fat soy flour from direct acid treatment retained about 90% of trypsin inhibitor activity regardless of treatment pH. More than 60% of the activity was removed from the full-fat soy material by whey separation. During soaking of soybeans more leaching was observed with higher acid concentration and soaking temperature. Urease activity was reduced to a commercially acceptable level (<0.2 $\Delta$pH) at the critical pH when lipoxygenase was inactivated.Protein insolubilization was minimized on neutralized soybean products after treatment at low pH. Using HCl as the acidifying agent, the PDI of sodium, potassium and calcium proteinate forms of full-fat soy flour treated at pH 3.0 were 74.9%, 76.4% and 70.3%, respectively. Using H\sb3PO\sb4 and tartaric acid, the PDI for the sodium forms were 78.5% and 76.4% respectively. The PDI for full-fat soy material after treatment at pH 3.0 was about 52-55%, irrespective of acidifying and neutralizing agents used. Production of lipoxygenase-free full-fat soy material was studied in terms of the composition and solid component recovery when treated at pH 3.0 during extraction prior to curd separation. The protein and fat content of the material were 47% and 25% and the yield of protein and fat were 85% and 72%, respectively.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD