Roasting process of carob pods at various temperatures for different times was carried out to study the effect of its process on the chemical constituents, minerals content, phenolic compounds and antioxidant activity. Volatile compounds were also determined for roasted carob powders. The obtained results revealed that the protein content was 5.42% (on dry weight basis), which decreased with increasing the processing temperatures. Whereas, ash increased gradually by increasing the roasted temperatures but lipids was decreased. The predominant mineral in carob powders was calcium followed by sodium, potassium and magnesium, respectively whereas; the raw carob pods contain 21.07mg/g of total phenolic compounds. Roasting treatment caused to the degradation of phenolic compounds which increased with increasing the roasting temperatures. The antioxidant activity of the carob powders was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) as free radical scavenging. However, the activity of antioxidant was decreased owing to the roasting process. On the other hand, sensory characteristics for both hot drinks and prepared cakes showed greater preference, especially for samples contained roasted carob powders at 160˚C for 30 min. and/or 40min. compared with that in tested samples and control. Seven aroma compounds were positively identified by using GC–mass spectrometry. The major aroma compounds of carob powders were 3-methyl butanal and methyl propanal which was found in chocolate and it's responsible for chocolate flavor. Moreover, other volatile compounds were identified in roasted carob powders and which also found in dark chocolate such as 2-Heptanone, Pentan-2-ol and Linalool. Also, Nonane-2-one and Hexanal were found and identified in roasted carob powders.

Natural antioxidants have gained considerable interest in recent years for their role in preventing the auto oxidation of fats, oils and fat containing food products. In this study, six spices containing natural antioxidants were evaluated for their re-tarding fat oxidation compared to butylated hy-droxyl toluene (BHT). The yield obtained from water extract of the tested spices ranged between 20% and 50 %. Carob gave the highest yield fol-lowed by anise and cinnamon, then caraway and fennel, while ginger gave the lowest yield .The free radical scavenging activities measured by 2-diphenyl-1-picryl-hydrazyl (DPPH) were 88.08%, 81.69%, 79.62% , 78.93% , 73.06% , and 71.50 % for cinnamon, anise, carob, caraway ginger, and fennel, respectively at concentration of 2250 μg/ml. Cinnamon showed higher antioxidant ac-tivity on linoleic acid oxidation than BHT fol-lowed by anise, carob and ginger. While, fennel and caraway recorded closely antioxidant activity to that of BHT at low concentration of 100 μg/ml. Total phenolic content of the tested spices varied ranging from 11.19 to 22.95 mg as gallic acid / gm dry extract in carob and caraway, respectively. Depending upon the sensory evaluation of crois-sant containing different levels of tested spices, a concentration of 1.5% of anise, caraway fennel and cinnamon was chosen, while the chosen con-centration of ginger was 2.5% and carob was 1% for testing their effectiveness against oxidation of lipid in croissant. However, a concentration of 2% of anise, fennel, ginger and carob was chosen while, the chosen concentration of caraway and cinnamon was 1% for testing their effectiveness against oxidation of lipid in filling cream. Addi-tion of tested spices gave an excellent antioxidant effect on croissant and filling cream compared with the effect of BHT. The increase in both per-oxide and acid values after 14 and 28 days respec-tively were lower than of control and BHT. Carob, ginger, caraway and cinnamon were more effec-tive in controlling lipid oxidation during storage. In conclusion addition of tested spices as sources of effective natural antioxidants retarded lipid oxi-dation and maintain the quality of croissant and filling cream during storage.