The current study was carried out to evaluate the shelf life of peeled shrimp during ice storage for 14 days using 125 µg/ml of crude isoflavones extract (CIE), 250 µg/ml of crude moringa extract (CME) and a mixture of both (62µg/ml CIE and 25µg/ml CME), as an antioxidant and antimicrobial agent. The results showed that using CME and/or CIE in ice improved the quality of peeled shrimp during ice storage. All treated samples showed; low content of total volatile nitrogen (TVN), trimethylamine (TMA), Thiobarbituric acid (TBA), cooking loss and free amino acids compared to the control sample, while the water holding capacity (WHC) of treated samples was increased. CME and/or CIE had a greater effect on spoilage microorganisms in treated samples of peeled shrimp, whereas the control sample reached the spoilage onset (10 7 log CFU/g) after eight days. In comparison, the treatment with CME and/or CIE additives prolonged the samples' shelf life to 14 days. Total bacterial count, Pseudomonas sp., Aeromonas sp. and Enterobactereace can be inactivated by CME or CIE. Significant differences were observed in mean sensory scores between treatments and control. The control recorded the lowest scores, while higher scores were obtained from the sample treated by CME plus CIE.

The present study was carried out to evaluate lemongrass's antimicrobial activities and probiotic cultures' viability in frozen yogurt. The yogurt was prepared with two different commercial starters of probiotics [Lactobacillus acidophilus (LA-5), Bifidobacterium lactis (BB-12)], incorporation with Streptococcus thermophiles and two various concentrations of lemongrass powder or extract (0.5% and 1%). The data showed that lemongrass extract inhibited all microorganisms' growth at a concentration of 36 µl/mL for fungi species (Aspergillus niger, Aspergillus flavus and Penicillium spp.) and 48 µl/mL for bacteria species (Pseudomonas fluorescens, aeruginosa, fragi and Aeromonas hydrophila, caviae, sobria). Lemongrass powder or extract produced an alternative, stable color and stable quality of yogurt during frozen storage. Sensory evaluation of frozen yogurt with lemongrass powder 0.5% had acceptable quality characteristics with higher antioxidant effect (Thiobarbituric acid values 1.02 mg malonaldehyde /kg) after 30 days of frozen storage. The viability loss during frozen storage of commercial probiotic cultures Lactobacillus acidophilus (LA-5) and Bifidobacterium lactis (BB-12) decreased between 0.7, 1.15 and 0.76, 1.36 log CFU/g, respectively in all treatments. The population of these microorganisms remained above 10 5 CFU/g.