Effect of the Diets Supplemented with Artichoke and Shrimp by-Products on Obese Rats N.I.E. Abo Elnaga 1 , Mona I. Massoud 2 , Amal M. Abd El-Razek 3 ,Mohamed Emad A. Nasser 4 and Amany R. Elgazzar 1 DOI: 10.21608/asejaiqjsae.2021.169609 1 Home Economics Dept Agric., Fac. of Agric. El-Shatby, Alexandria Univ., Alexandria, Egypt. 2 Sugar Crops Research Institute, Agric. Research Center, El-Sabahia, Egypt. 3 Food Science & Technology Dept., Fac. of Agric. El-Shatby,21545, Alexandria Univ., Alexandria , Egypt 4 Dept.of animal and Fish Production, Fac. of Agric. El-Shatby, Alexandria University, Alexandria , Egypt. Received April 04, 2021, Accepted May 05, 2021. ABSTRACT Foods supplemented with functional fiber are an effective means for prevention of diseases like obesity, cardiovascular diseases, and diabetes mellitus. The objective of this study was to estimate the dietary fiber content in artichoke stems by-product powder (ASP) and shrimp by-product powder (SBP) and evaluate the protective effect of diet supplemented with their by- products as natural dietary fiber on weight gain, the blood picture, serum biochemical parameters and liver enzymes activities in obese rats. The results revealed that the crude fiber content was 22.68% in the ASP and 13.65% in SBP. Total dietary fiber fractions were composed of 18.69 and 0.42% soluble dietary fiber, 25.01 and 58.57% insoluble dietary fiber in defatted ASP and SBP, respectively. They also presented high amounts of inulin (18.2 g/100 g artichoke stem) and chitin (58.15 g/100 g shrimp shell). Biological impacts were done on the control group (CG) and compared with obese rat groups which were classified into seven groups; positive group (PC) and groups fed on diet supplemented with ASP and SBP at a level of 5 and 10%, inulin at dose 7.7 %, and chitosan at dose 2.6 %, for 8 weeks. The results showed significant improvement and ameliorated reduction in final body weight, body weights gain (%) and feed efficiency ratio (FER) in all the treated groups compared with the PC. Administration of 10% ASP or SBP significantly decreased body weight by 37.66 and 35.61%, respectively as compared to the high fat diet (HFD) group, while the highest reduction in body weight gain and lower FER were obtained in groups fed on chitosan. Feeding obese rats on diet containing ASP and SBP led to a reduction in the total cholesterol, triglycerides, and low-density lipoprotein cholesterol concentration, decreased in blood glucose level and improved serum liver enzymes activity and antioxidant enzyme activity as compared to the positive group. ASP as a source of inulin and SBP as a source of chitin can be used in the nutraceutical formulation of functional food products and a good source of natural dietary fiber to enhance the nutritional quality for prevention of diseases like obesity, and its associated health risks. Keywords: Functional fiber, natural dietary fiber, inulin, chitin and nutraceutical. INTRODUCTION There is a worldwide interest with natural dietary fiber that possess many beneficial nutritive and physiological effects in humans such as enhancement of immune system, improvement of digestive functions and reduces risk for developing some diseases like obesity, heart disease, diabetes, dyslipidemia, hypertension and osteoarthritis (Fernstrand et al., 2017 and Siracusa et al., 2019). A promising source of functional compounds is food by-products because of their nutritional and rheological properties where they are composed of protein, fats, nondigestible carbohydrate, bioactive compounds, and phytochemicals. Vegetable-by- product such as artichoke by-product is a source of inulin and rich source of bioactive compounds which protect against heart disease and cancer (Fratianni et al., 2007). Inulin known as fructans, is a polysaccharide, consisting of polymer of fructose with β (2-1) glycosidic linkage. Inulin is a prebiotic non-digestible dietary fiber that beneficially affects the host by selectively stimulating the growth of beneficial bifidobacteria, production of short chain fatty acids (SCFAs), calcium absorption, decrease in body weight gain and thus improves immune health (Franco-Robles and López, 2015 and Mohanty et al., 2018). Seafood wastes such as shrimp shell is the most abundant source of chitin as a natural biopolymer after cellulose as well as, it contains 30-40% protein, 30-50% calcium carbonate and calcium phosphate (No and Meyers, 1995). Chitin is a linear polymer of anhydro N- acetyl glucosamine, and can be converted into chitosan, chito- oligosaccharides and glucosamine augments its biological properties and applications in various industries such pharmaceuticals, and food industries