Application of sugar alcohols and artifical sweeteners as substitutes for sucrose in apricot, peach and strawberry jams.

Preparation of acceptable low caloric jams and replacement of sucrose by other sweeteners in jam were studied. Peach, apricot and strawberry jams were sweetened with sucrose [as control], aspartame, sorbitol or with combinations of them. It was possible to prepare jams with lower amounts of sucrose than currently used and still attain an acceptable product. When aspartame was used as the only sweetening agent, apricot, peach and strawberry, jams slight increase in total soluble solids, acidity and retention of vitamin C. Both aspartame and sorbitol were found to be heat stable and their sweetness did not change during processing. Also they had no effect on the total phenolic compounds. Jam prepared with 100% aspartame was much more viscous than 100% sorbitol in all jam samples. Finally, it could be concluded that energy value of each of the three tasted fruits prepared with the addition of 100% sorbitol showed lower calorie content [kcal/100g]. There were no differences in the color of the test jams except the color of strawberry jam was somewhat lower by using 100% aspartame. These results are in coincidence with the sensory evaluation that low calorie apricot, peach and strawberry jams with good color, texture and taste can be prepared from aspartame, sorbitol or mixture of them

Effect of varying salts concentration on physical, chemical and sensory characteristics of chicken meat

Increasing of sodium chloride concentrations decreased the pH and increased protein solubility from chicken breast muscle [CBM] and chicken thigh muscle [CTM] samples. It was observed that the protein solubility [PS] was increased by over 22% in CBM samples and by less 20% in CTM samples at 5% NaCl after 1 hr soaking. While PS was increased by 18% in CBM Samples and by 14% in CTM. No pronounced different in cooking loss between the two samples. The results showed more reduction in CTM samples after 1 hr soaking in 5% NaCl than in CBM samples. Furthermore, transmission of both types of CBM and CTM decreased slowly with the increasing of salt solution. Also, high salt concentration at level 5% NaCl reduce chicken muscle shrinkage and providing firm textures through solubilization of muscle proteins. At 4% and above, salt did not significantly increase the gel liquid lost, but the further reduction by 31% to 2% salt, significantly released more gel liquid compared to 4% salt concentration. The water holding capacity [WHC] of CBM samples was higher than those of CTM samples due to the CBM protein content which is higher than CTM. Different concentrations of sodium chloride solutions caused the release of some proteins and henced the unfolding proteins and caused the release of the carboxyl groups [-COOH], hence it caused the release of pH in the media. Increasing the concentration of the salt from 2% to 5% does not achieve any effect on folding the proteins because all the proteins are release from the Alpha-helix structure hence the gel electrophoresis band are becoming obviously seen and caused a pH stability even with increasing extraction time. Low concentration of mono-valiant salts does not lead to enhancing the appearance of high molecular weight protein approximately 200 kD, but low concentration of divalent salts enhanced the appearance of high molecular weight protein. Data showed panelists acceptability towards soaking CBM and CTM samples in 4% NaCl for 1hr, while samples were soaking in 1% MgCI[2] showed unacceptability

Chemical and technological studies on sweet potatoes

Boiled sweet potatoes [Ipomoea batatas] were used as a basis for preparation of different formulas. The blends were consisted of sweet potatoes plus wheat germ, skim milk powder or honey at ratios of 5, 10, 15 and 20%. The influence of fortification on the chemical composition and sensory properties of different formulas was also investigated. The results obtained indicated that skim milk powder and wheat germ are rich in proteins [35.6% and 27.3%, respectively] as well as most essential and non-essential amino acids. The fortification of sweet potatoes with skim milk powder or wheat germ increased the protein content of prepared formulas, while fortification with hony increased the carbohydrate content. Sweet potato formulas fortified with wheat germ or skim milk powder had mineral contents higher than that of sweet potatoes fortified with honey. There were slightly significant differences in colour between formulas. Results show that sweet potatoes fortified with honey were highly accepted for their appearance, colour, stickiness and sweetness and were superior to other samples. On the other hand, sweet potatoes fortified with skim milk powder and honey were superior in taste and chewiness than sweet potatoes fortified with wheat germ, but the odour in sweet potatoes fortified with skim milk powder was superior than other samples. Moreover, the sweet potatoes fortified with 10% honey or 10% skim milk powder were highly accepted and were superior than other samples and control. Sweet potatoes fortified with 10

Utilization of taro flour in manufacture of pan bread and cookies

Whole taro [Colocassia esculenta L.] flour was prepared from local [Balady] taro corms and to prepare free mucilage taro flour was obtained after removing taro mucilage by steeping in 4% NaC1 solution and washing with boiling water. Levels of 5,10,15,20, 25 and 30% taro flour [whole or without mucilage] were used to substitute wheat flour [72% ext.] for prepared pan bread and cookies. The effect of substitution on the chemical composition, mineral contents, rheological properties of blended flours, baking quality and acceptability of pan bread and cookies were investigated. Considerable increases of 400% or 466.7% in crude fiber and 391% or 584% in ash and detectable a decreases of 7.8% or 9.9% in proteins and 7.2% or 2.1% in starch occurred when taro flour [whole or without mucilage] substitution was increased from 0% to 30%, respectively. Mineral contents except Zn and Cu, were increased gradually with increasing taro flour [whole or without mucilage] substitution. Farinograph and Extensograph rheological data revealed that, water absorption percent and dough weakening were increased with increasing the ratio of taro flour substitution, and all the studied flour mixtures had low extensibility compared with the control [100% wheat flour]. The largest decrease in baking quality of bread were observed for the higher levels taro flour substituted bread. However, control bread, whole taro flour [with mucilage] substituted bread up to 15% and free mucilage taro flour substituted bread at level of 5% showed superior baking quality and sensory parameters. However, substituted cookies by 15% whole taro flour or 25% free mucilage taro flour gave the highest scores for most sensory attributes. In general, it could be concluded that acceptable bread or cookies may be prepared by mixing wheat flour with taro flour [whole or without mucilage] at definite ratio of substitution [15% or 5% and 15% or 25%,respectively]

Effect of storage and cooking on the proteins in ground beef patties

While it is known that meat flavor varies as a function of endpoint cooking temperature, storage time, and activity of endogenous hydrolytic enzymes, little is known about the interrelationship of these three factors with flavor. Several endogenous enzyme and proteins with potential involvement in meat flavor were investigated. Results suggested that several proteins TPI, LDH, PGAM, and AP, might be useful in assays to verify processing temperatures of cooked ground beef patties. None of the enzymes were completely inactivated at the heating temperature we used and the activity slowly decrease in storage. SDS-PAGE has gained wide application in monitoring the proteolytic degradation of myofibrils. By high temperature band has small molecular weight proteins disappeared and high molecular weight proteins quantitatively decreased. The pink color was mainly observed at high temperature due to incomplete denaturation of myoglobin during cooking. High cooking temperature increase the reducing environment in meat. Increasing storage time resulted in beef patties samples lower in juiciness, tenderness, flavor desirability and overall palatability