No description available.

No description available.

No description available.

Biscuits were prepared from eighteen different recipe formulations. The biscuits were made from flour containing 7.53%, 8.99%, and 10.05% protein with 30, 40, and 50 grams of shortening and 0 or 2.2 grams of microcrystalline cellulose (MCC). Biscuit quality was assessed by objective and sensory evaluation. The caloric content of the biscuits was also determined by bomb calorimetry. No significant differences were detected in biscuit volume, crumb and crust color, or tenderness. The biscuits prepared with lower levels of shortening were moister than the biscuits prepared with higher levels of shortening. Wo significant differences were found by sensory panelists with regard to evenness of exterior color, aroma, evenness of cell structure, size of cell structure, interior color, center moistness, tenderness, biscuit flavor, or aftertaste. Flakiness and exterior color were found to be significantly different. Biscuits with added MCC were detected to be less flaky. Biscuits prepared from medium protein level flour and low-shortening with MCC were darker than high-shortening biscuits without MCC. High-protein, high-shortening biscuits with MCC were darker than medium-protein, high-shortening biscuits without MCC. The caloric content of the biscuits prepared with lower amounts of shortening was found to be significantly less than biscuits prepared with the higher levels of shortening. In conclusion, high quality biscuits can be produced from flour of varying protein content with less shortening and without the incorporation of MCC. / Master of Science

Call number: LD2668 .T4 1985 M375 / Master of Science

Call number: LD2668 .T4 1985 V36 / Master of Science

No description available.

Thesis (M.B.A.)--University of Hong Kong, 1982.

New Fourier transform infrared (FTIR) approaches for the quantitative determination of peroxide value (PV) and isolated trans analyses were investigated and developed. The FTIR-PV methods investigated were all based on the stoichiometric reaction of hydroperoxides and triphenylphosphine (TPP) which converts TPP to triphenylphosphine oxide (TPPO). A reference transmission cell (100 mum) method was developed based on the use of a unique TPPO absorption at 542 cm-1. This method covered PV values from 0--15 PV and was shown to be superior in accuracy and reproducibility to the standard American Oil Chemists Society (AOCS) iodometric method. Subsequently, the utility of disposable polyethylene cards, normally used only for qualitative analyses, was investigated for quantitative PV determination. A quantitative IR card method was successfully developed and shown to serve as a very simple, rapid and alternative means of carrying out PV analyses. TPP-impregnated cards were able to reproduce the transmission cell PV results to +/-1.12 PV, while the unimpregnated card was slightly more accurate (+/-0.92 PV). A third FTIR-PV method was developed specifically for the at-line monitoring of high PV fatliquors and employed a germanium attenuated total reflectance sample handling accessory. This method hinged on the use of a TPPO absorption band at 1118 cm-1, normally off scale when pathlengths of >3 mum are used, but is suited to the analysis of oils having very high PVs (>250). The successful quantitative use of the disposable polyethylene IR card to PV led to its study for the quantitative FTIR determination of the isolated trans content of fats and oils and margarines. The polyethylene card was shown to unique and useful properties, tending to inhibit fat crystallization and its inability to retain moisture. These two properties allowed trans determination to be carried out on melted, high trans fats, without heating the polyethylene substrate and also to analyze margarines

Lipid oxidation has important consequences in the edible oil industry, producing compounds with sensory impact and thus reducing the economic value of the products. This work focused on the development of two Fourier transform infrared (FTIR) spectroscopy methods for the measurement of peroxide value (PV) and anisidine value (AV), representing the primary and secondary oxidation products of edible oils. / The infrared method developed for PV determination was based on a mathematical treatment by the partial least squares method of the information contained in the spectral region between 3750 and 3150 cm$ sp{-1}$. / The second method developed considered aldehyde content and anisidine value, a measure of secondary oxidation products. / The two methods developed are rapid ($ sim$2 min/sample) and have the advantage of being automatable. An infrared system coupled to a computer can collect the spectrum of an oil, analyze it and present a report without the need for personnel trained in FTIR spectroscopy. The cost of such a system would rapidly be absorbed through savings on personnel cost, time and chemical reagents required for conventional chemical methods and as such provides a useful advance in quality control methodology for the edible oils sector. (Abstract shortened by UMI.)