Hichem Ben Salem

Phytochemical content and antioxidant properties of diverse varieties of whole barley (Hordeum vulgare L.) grown in Tunisia

Four varieties (Rihane, Manel, Roho, and Tej) of Tunisian barley were analysed for their antioxidant activities (AA) using ABTS and DPPH radicals cation, and ferric reducing/antioxidant power (FRAP) methods. The total phenolic (TPC), total flavonoid (TFC) and condensed tannins (CTC) contents were measured. The results indicated that the total phenolic contents ranged from 195.02 ± 0.32 to 220.11 ± 0.32 mg gallic acid equivalent/100g fresh weight. Results showed that Rihane has the highest TPC, TFC and CTC compared to other varieties. Roho barley had a lower activity than Tej barley. A significant correlation (p<0.05) was found between TPC, TFC, CTC and AA. This study suggests that Tunisian barley varieties may serve as a good source of natural antioxidants.

Effect of the dietary supplementation of essential oils from rosemary and artemisia on muscle fatty acids and volatile compound profiles in Barbarine lambs

Eighteen Barbarine lambs (3 months of age), were assigned for 95 days to 3 treatments: six lambs were fed a barley-based concentrate plus oat hay ad libitum (control group, C); other lambs received the control diet plus essential oil (400 ppm DM) either of Rosmarinus officinalis (R400 group; n=6) or of Artemisia herba alba (A400 group; n=6). At slaughter the muscle longissimus dorsi was sampled and subjected to fatty acid and volatile organic compounds (VOC) analyses. The A400 lambs presented a greater amount of vaccenic, rumenic and linolenic acids and of polyunsaturated fatty acids (PUFA) in meat than the C and R400 animals. Essential oils supplementation did not affect meat VOC profile though the sesquiterpenes copaene and β-caryophyllene were detected only in the meat of R400 and A400 lambs. It is concluded that the supplementation of rosemary or artemisia essential oils does not produce detrimental effects on lamb meat VOC profile. The supplementation of artemisia can improve meat healthy properties.

The antioxidant status and oxidative stability of muscle from lambs receiving oral administration of Artemisia herba alba and Rosmarinus officinalis essential oils

The effect of the dietary supplementation to lambs of essential oils (EOs) from rosemary (Rosmarinus officinalis) and artemisia (Artemisia herba alba) on the antioxidant status of muscle and on meat oxidative stability was studied. Eighteen Barbarine lambs were divided into 3 groups and for 95days received oat hay and concentrates. One group (C) was not supplemented, while the other two groups received 400mg/kg of EOs from rosemary (R400) or artemisia (A400). Both EOs possessed antioxidant properties and their oral administration improved the reducing and radical scavenging capacity of the muscle compared to the C treatment (P<0.01). Nevertheless, supplementing EOs did not exert protection against lipid oxidation and did not affect the colour stability in meat over 7days of aerobic storage.

Attenuation of histopathological alterations of colon, liver and lung by dietary fibre of barley Rihane in azoxymethane-treated rats.

This study was carried out to determine the effect of dietary fibre (DF) of barley Rihane (BR) in the attenuation of colon, liver and lung histopathology alterations induced by azoxymethane (AOM) in rats. Rats were fed a control (C) or experimental diet containing 30% of BR. The intended rats for cancer treatment received two successive subcutaneous injections of azoxymethane (AOM) at 20mg/kg body weight. The colons were analyzed for crypt multiplicity after 12 weeks of treatment. A histological study of the colon, liver and lungs was determined. The results showed that the BR diet significantly reduced the number of aberrant crypt per focus and altered their distribution. In addition, DF of BR increased significantly the mucus secretion compared to control group. The use of the AOM as colon specific carcinogen substance altered the liver and lung architectures, whereas the presence of DF of BR could be a protective factor for these organs.

Improving the nutritive value of Olive Cake by solid state cultivation of the medicinal mushroom Fomes fomentarius

Olive Cake (OC) generated by the olive oil industries, well implanted in Tunisia, represents a major disposal and potentially severe pollution problem. This work presents the study of bioconversion of OC in solid state fermentation with the medicinal mushroom, Fomes fomentarius so as to upgrade its nutritional values and digestibility for its use as ruminants feed. The fungus was cultured on OC for 7-30 d, and subsequently the chemical composition, lignocellulolytic enzyme activities and in vitro digestibility of the resultant substrate were determined. The results obtained showed an increase in the crude protein ranging from 6% to 22% for the control and for treated OC, respectively. Significant (P<0.05) decreases in the values of neutral detergent fiber (hemicelluloses, cellulose and lignin), acid detergent fiber (lignin and cellulose) and acid detergent lignin were detected (23%, 13% and 10%, respectively). The estimated in vitro digestibility improved from 9% (control) to 25% (treated OC). The present findings revealed F. fomentarius to be an efficient organism for lignocellulolytic enzymes production and simultaneous enhancement in crude protein and in vitro digestibility of OC.

BIOCHEMICAL COMPOSITION AND NUTRITIONAL EVALUATION OF BARLEY RIHANE (HORDEUM VULGARE L.)

Background: Many experimental studies have suggested an important role for barley Rihane(BR)in the prevention of colon cancer and cardiovascular diseases. The objective of this study was to evaluate the physico-chemical properties and nutritional characterizations of BR compared to other varieties grown in Tunisia (Manel, Roho and Tej). Material and Methods: Total, insoluble and soluble dietary fiber(β-glucan), total protein, ash and some minerals of BR and Tunisian barley varieties were determined. Results: The results revealed that BR is good source of dietary fiber mainly β-glucan compared to the other varieties. This variety is a relatively rich source of phosphorous and potassium and it contains many important unsaturated fatty acids. BR has higher nutritional value than other varieties. Conclusion: Barley Rihane has significant nutritional characterizations compared to others Tunisian barleys varieties. Abbreviations: BR, Barley Rihane; LDL, low density lipoprotein; HDL, high density lipoprotein; AOM, azoxymethane; TBV, Tunisian barley varieties; TGW, thousand grain weight; SW, weight specific; TDF, total dietary fiber; IDF, insoluble dietary fiber; SDF, soluble dietary fiber; DM, Dry Matter.

Global Warming and Livestock in Dry Areas: Expected Impacts, Adaptation and Mitigation

In most developing countries livestock is the key asset for rural people providing multiple economic, social and risk management functions. Rangelands contribute to the livelihoods of over 800 million people including poor smallholders. The arid area of the globe is home for extensive livestock production mainly based on small ruminants (Ben Salem & Smith, 2008). The most important sheared characteristic of such zones, despite the high variety of biotopes, is aridity with a very erratic pattern of rainfall and extended periods of high temperatures. These two factors together with a higher frequency of extreme climatic events will be amplified under the perspective of global warming thus affecting negatively food availability through the seasons of the year. The impacts that climate change will bring about are expected to exacerbate the vulnerability of livestock systems and to reinforce existing factors that are simultaneously affecting livestock production systems such as rapid population and economic growth, increased demand for food and products, and increased conflicts over scarce resources (e.g. land tenure, water, and feed). There is an urgent need for detailed assessment of climate change impacts in each production system and for identifying appropriate options that can help livestock keepers adapt to climate change. This chapter summarizes current knowledge on global warming, discusses its impacts on the different components of the production systems and reports technical options to overcome negative effects of climate change on the livestock productivity and health and sustainability of livestock-based production systems. The approach recommended to transfer and adopt these options is also discussed.