الفهرس 
INTRODUCTION
Aim of investigationOnly 14 pages are availabe for public view
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Abstract
This investigation was carried out to study the production of liquid smokes from some agricultural wastes such as beech sawdust, sugarcane bagasse, rice husk and corncob. Cellulose and lignin were assessed from these agricultural wastes. Production yield, pH, acidity, antioxidant activity, antimicrobial activity, chemical volatile components, heavy metals, polycyclic aromatic hydrocarbons and biological evaluation were performed from produced liquid smokes. Meanwhile, beech sawdust, sugarcane bagasse, rice husk and corncob liquid smokes were used as preservatives and flavoring agents to produce smoked bayad fish fillets and kesher bayad fish balls. Chemical composition, chemical quality attributes, fatty acids, physical properties, fatty acids and organoleptic evaluation were determined for both studied products during chilled storage.
The most important obtained results from this investigation could be summarized as follows:
1. Liquid smoke production
- Data showed that cellulose and lignin contents were (40.07%, 23.20%), (38.62%, 22.17%), (49.38%, 25.70%) and (23.45%, 20.24%) for beech sawdust, sugarcane bagasse, rice husk and corncob; respectively.
- The yield of liquid smoke was highest from the corncob (48.50%), followed by the sugarcane bagasse (44.30%), the beech sawdust (42.00%) and the least from rice husk (34.50%).
- All studied liquid smokes had pH under 4 so these results indicated that all liquid smoke inhibited the growth of bacteria. The rice husk liquid smoke had the highest acidity 9.51% with pH of 2.87 and acidity (% acetic acid) with a statical significant difference P < 0.05than that of other liquid smokes. This might be due to that rice husk had high cellulose content than other materials. On the other hand, the corncob liquid smoke had a higher pH and lower acidity with pH of 3.55.
- All liquid smokes had strong DPPH free radical scavenging activity (4.29–89.24% inhibition). The highest radical scavenging activity was observed with significant difference p < 0.05 in rice husk liquid smoke, while, corncob liquid smoke had the lower activity than other all liquid smoke and all liquid smokes had lower activity with significantly (p < 0.05) under level 15 µg. Antioxidant activity of different liquid smokes and BHT exhibited the effectiveness followed the sequence BHT > rice husk > beech sawdust > sugarcane bagasse > corncob liquid smokes.
- Data revealed that the larger zones of inhibition were observed for the Gram positive bacteria (Bcillus subtilis and Staphylococcus aureus), while the lower for Gram negative (Escherichia coli and Salmonella typhimurium). Moreover, results revealed that beech sawdust and sugarcane bagasse had moderate inhibition against Aspergillus niger. Meanwhile, rice husk and corncob had no inhibitory effects on Aspergillus niger. All different liquid smokes had no inhibitory effects on Fusarium oxysporum. Whereas, Candida albicans was inhibited by all different liquid smokes, also all different liquid smokes had strong inhibition against Saccharomyces cerevisiae.
- Many chemical components were identified by GC/MS and fractionated to acids and esters, phenol derivatives, carbonyl derivatives, furan derivatives and other compounds for beech sawdust, sugarcane bagasse, rice husk and corncob liquid smokes. Furthermore, high percentage of phenol compounds were found in rice husk liquid smoke.
- Results indicated that the level of arsenic, cadmium, lead and mercury were below their respective limits in all studied liquid smokes.
- All studied liquid smokes were found free of benzo[a]pyrene carcinogenic compound. Benzo[a]anthracene was detected in rice husk and corncob liquid smoke but the levels of benzo[a]anthracene at both liquid smoke were below the respective limits of 20 μg/kg.
- A 90-day oral toxicity study of smoke flavoring was performed in male rats. Data of body weight indicated that there were gradual increase with significant differences P<0.05 were observed for all different groups during feeding time for 90 days.
- The activities of (ALT) and (AST) were determined in rats serum to evaluate the effect of different liquid smokes on liver functions. Results indicated that the rats feeding basal diet containing 3000 and 9000 mg/ kg diet of different studied liquid smokes had significant decrease P<0.05 of alanine amino transferase (ALT) and aspartate amino transferase (AST) except rats feeding basal diet and 3000 mg/kg diet of rice husk and corncob liquid smokes had significant increase P<0.05 compared than that of control group. Creatinine level were significantly lower (P<0.05) in all studied liquid smokes treated compared with control group. Rats feeding basal diet containing 9000 mg/kg diet had significantly higher (P<0.05) of creatinine level than groups feeding basal diet and 3000 mg/kg diet of different liquid smokes. Results indicated that uric acid for rats feeding on a basal diet for 12 weeks was 1.23 mg/dl. While, feeding rats on a basal diet containing (3000, 9000 mg/kg diet) of beech sawdust, sugarcane bagasse, rice husk and corncob liquid smokes for 12 weeks had increment with significantly effect (P<0.05) on blood serum uric acid level.
- The histopathology of organs revealed no any tumor and abnormalities related to liquid smoke toxicity and all studied liquid smokes had the same effect on liver and kidney tissues.
2. Application of beech