الفهرس 
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Abstract
Part I
(Survey part)
Evaluation of the hygienic aspects of dried kinds of milk and infant formulas
This investigation was applied to explore the hygienic aspects of different dried milks and infant formulas procured from different supermarkets and pharmacies in Assiut City, Egypt. All the samples were examined for sensory, physical, chemical, and microbiological parameters.
For the sensory examination, most of the examined samples of dried kinds of milk and infant formulas were of good sensory quality. The physicochemical examination was expressed in the insolubility index, pH, acidity, moisture, TS, fat, and SNF. The average physicochemical results were 2.3 mg, 6.95, 0.14%, 4.2%, 95.8%, 36.4% and 59.4% in the examined unpacked dried milk, respectively; 5.26 mg, 6.92, 0.15%, 3.1%, 96.9%, 32% and 65% in the examined packed whole dried milk samples, respectively; 2 mg, 6.92, 0.13%, 3.4%, 96.9%, 4.8%, and 91.8% in the examined packed skim dried milk samples, respectively. For the infant formulas samples, the average physicochemical results were 2.3 mg, 7, 0.05%, 2.8%, 97.2%, 4.1% and 93.13% for the company 1, respectively; 3.3 mg, 7, 0.06%, 4.4%, 95.6%, 4.5% and 91% for the company 2, respectively; 0.97 mg, 7, 0.05%, 3.6%, 96.5%, 5.1% and 91.4% for the company 3, respectively.
Regarding the microbiological results, coliforms, fecal coliforms, and E. coli results were acceptable according to the Egyptian Standards for all the examined samples. Moreover, all the samples were Cronobacter-free. The incidences of B. cereus, Cl. perfringens, and anaerobes were 40, 6.67 and 33.33% in the unpacked dried milks, respectively; 20, 10 and 80% in the packed whole dried milks, respectively; 40, 0 and 20% in the packed skim dried milks, respectively; 10, 0 and 10% in the infant formula of the company 1, respectively; 0, 0 and 20% in the infant formula of the company 2, respectively; 70, 10 and 40% in the infant formula of the company 3, respectively.
The average yeast & mold counts were 1.4x105, 1.3x105, and 7.3x103 in the examined unpacked, whole-packed, and skim-packed dried milk, respectively; and 5.9x103, 1.4x104 and 3.1x105 in the examined infant formulas for the companies 1, 2 and 3, respectively.
Part II
(Experimental part)
Effect of Storage Temperatures on quality of dried milk and infant formulas
The experimental part was applied to explore the effect of storage temperatures on the quality of the previously examined dried milk and infant formulas. All the samples were examined for sensory, physical, chemical, and microbiological changes after storage for 3 months in a refrigerator, incubator (37° C), and room temperature.
For the sensory examination, most of the examined samples of dried milk and infant formulas were of good sensory quality after different storage temperatures. The physicochemical results revealed a high significant increase in titratable acidity after the storage in the incubator and at room temperatures for all the dried milks. Moreover, there was an increase in the moisture content in the whole and skim-packed dried milk stored at room temperature. For the physicochemical results of the infant formulas, there was an increase in the titratable acidity and moisture after storage.
Concerning the microbiological examination, all the samples were within the permissible limit of the Egyptian Standards for coliforms, fecal coliforms and E. coli counts after storage. B. cereus increased in the skim-packed dried milk and the infant formulas of company 2 after storage in different temperatures. Cl. perfringens increased after storage at room temperature in the dried milk. The yeasts & molds increased in the unpacked dried milk and the infant formulas of the company 2 after storage in the different temperatures.