Bioconversion of alperujo into an alternative feed for ruminants by pretreatment with live yeasts and/or exogenous fibrolytic enzymes.

Extraction of olive oil through a two-stage centrifugation process produces a large amount of phytotoxic waste known as alperujo. This research was performed to bioconvert alperujo into enriched ruminant feed by pretreatment with exogenous fibrolytic enzymes (EFE) or/and live yeasts (LY). These additives were used in a completely randomized design with 3 EFE doses (0, 4, and 8 µl/g dry matter) and 3 LY doses (0, 4, and 8 mg/g dry matter) in a 3 × 3 factorial arrangement. Fermented alperujo with both EFE doses converted some of their hemicellulose and cellulose to simple sugars and increased bacterial abundance in the rumen. As a result, it shortens the lag time of rumen fermentation, increases the rate and amount of rumen fermentation, and improves digestibility. This improvement provides additional energy that can be used by ruminants to produce milk and by rumen microbiota to produce short-chain fatty acids. Fermented alperujo with a high dose of LY decreased their antinutritional compounds and reduced their high content of lipid. In the rumen, this waste became rapidly fermentable, and rumen bacteria became more abundance. Fermented alperujo with a high dose of LY + EFE accelerated rumen fermentation and improved rumen digestibility, energy available for milk production, and short-chain fatty acids compared to the use of LY or EFE alone. This synergistic interaction between these two additives increased protozoa abundance in rumen and the ability of rumen microbiota to bioconvert ammonia-nitrogen to microbial protein. Ultimately, fermentation alperujo with EFE + LY is a good strategy with minimum investment for a social sustainable economy and environment.

Study of the influence of exogenous fibrolytic enzyme additive on chemical composition, fermentation characteristics, and nutritional value of brewer's spent grain.

This study explores the influence of different doses of two exogenous fibrolytic enzyme (EFE) additives (liquid (EFE1: 1, 2, and 4 µΙ/g DM (dry matter)) and powder (EFE2: 1, 2, and 4 mg/g DM)) on the chemical composition, fermentation characteristics, and nutritional value of brewer's spent grain (BSG). The results indicate that EFE1 at low doses does not affect the chemical composition, fermentation characteristics, and the nutritional value of BSG. The medium dose EFE1 decreases the fiber compound but increases the nonfiber carbohydrates (NFC) and soluble dry matter. Also, this dose modified the fermentation of BSG by increasing the amount of gas and its fermentation rate and decreasing the time between the inoculation and start of fermentation. Therefore, it increases the digestibility, metabolizable energy, net energy-lactation (NEL), total volatile fatty acids, and the microbial crude protein production of BSG. The high dose of EFE1 decreases the fiber compound and increases the nonfiber carbohydrates and soluble dry matter; however, it also decreases the potential of gas production and does not affect the nutritional value of BSG. For EFE2, all the doses do not modify the chemical composition, fermentation characteristics, and the nutritional value of BSG. These results suggest that the effectiveness of EFE varied, depending on the type of EFE and dose. Increase in the nutritional value of BSG by EFE1 at the medium dose can encourage breeders to use these wastes as feed at low cost in cow nutrition.

In vitro study on the effects of exogenic fibrolytic enzymes produced from Trichoderma longibrachiatum on ruminal degradation of olive mill waste.

Olive mill waste is low-quality feed and rarely used in ruminant nutrition because of its high lignocellulose content, the existence of anti-nutritional factors such as total polyphenol and condensed tannin, and low protein contents. This in vitro research was conducted to valorize this waste (crude olive cake, extracted olive cake, and olive leaves) using an exogenous fibrolytic enzyme produced from Trichoderma longibrachiatum in ruminal nutrition. The enzymatic activity of this additive was 1161 units of endoglucanase per millilitre, 113 units of exoglucanase per millilitre, and 2267 units of xylanases per millilitre. This treatment was applied by spraying substrates with four doses: 0 (control), 1 (low), 2 (medium), and 4 µ L g - 1 µ L g - 1  (high) of dry matter olive mill waste in an air-conditioned room at 26  ∘ C for 12 h before in vitro incubation. For the crude olive cake, this additive at high doses increased degradation of 14 % of cellulose and 8 % of hemicellulose compared with the control at 12 h before the in vitro incubation. Consequently, it increased dry matter solubility and reduced sugars at this period compared to the control. Upon ruminal incubation, the high dose of exogenous fibrolytic enzyme increased the gas production from the immediately soluble fraction and insoluble fraction, the rate of gas production for the insoluble fraction, the dry matter degradability by 26 %, the organic matter degradability by 24 %, the metabolizable energy value by 28 %, and the microbial crude protein production by 24 % compared with the control. For olive leaves, an exogenous fibrolytic enzyme at medium dosage can also hydrolyse the hemicellulose compound, release fewer sugars, and increase dry matter solubility compared with the control at 12 h before the in vitro incubation. Upon in vitro incubation, the medium dose increased the gas production from immediately soluble and insoluble fractions, the rate of gas production for the insoluble fraction, the dry matter degradability by 13 %, the organic matter degradability by 11 %, the metabolizable energy value by 12 %, and the microbial crude protein production by 12 % compared with the control. However, the highest dose altered the gas production from insoluble fractions and decreased microbial crude protein production by 6 % compared with the control. Under the same conditions, an exogenous fibrolytic enzyme applied to extracted olive cake did not produce any effect in the chemical composition and nutritional value. These results showed clearly that effectiveness of exogenous fibrolytic enzyme varied with incubated waste. Increasing the nutritional value of crude olive cake and olive leaves using an exogenous fibrolytic enzyme can encourage breeders to use this waste as feed at a low cost in animal nutrition. This valorization of waste is a good solution to reduce pollution of soils and groundwater caused by throwing out this polluted waste into the environment.

Chemical, physical and sensory characteristics of biscuits enriched with jujube (Zizyphus lotus L.) flour and fiber concentrate.

The present study was undertaken to evaluate the effect of partial wheat flour substitution by jujube flour (JF) or jujube fiber concentrate (JFC) (0-15%) on chemical, physical and sensory quality of biscuits. JFC extracted from jujube pulp was characterized by high fiber (89.61% DM) and phenolic (6.8 mg GAE/g) contents and showed good functional properties. Textural characteristics of biscuit doughs weren't negatively affected by wheat flour substitution. The enriched biscuits with JF or JFC showed improved nutritional quality proved by an increase in dietary fiber, ash and total phenolic contents. No variations were observed for the weight, thickness, diameter and spread ratio of enriched biscuits as compared with the control. Biscuit hardness increased, but L* values decreased significantly with the substitution level. Regardless the JF level, sensory quality of biscuits was acceptable. For JFC, a maximum of 10% can be incorporated to obtain desirable biscuits quality.

Effect of extraction procedures on the chemical structure, antitumor and anticoagulant properties of ulvan from Ulva lactuca of Tunisia coast.

The effect of extraction procedures on chemical composition, structural, antitumor and anticoagulant properties of the sulphated polysaccharide 'ulvan' from the green seaweed Ulva lactuca were investigated. The structural features of ulvans were carried out by FTIR and by one- and two- dimensional 1H and 13C NMR spectroscopic. The ulvans were mainly composed of rhamnose, xylose, and uronic acid. Chemical and spectroscopic analyses demonstrated that ulvans were constituted of (1→4)-ß-glucuronic acid, (1→3,4)-α-L-rhamnose-3-sulphate and (1→4)-α-xylose. The extraction procedures effect were observed in chemical structure, Mw and biological activities. Cytotoxic activity of enzymatic-chemical extract on cervical cancer cells (HeLa) (IC50 = 1000 µg/mL) was higher than on normal peripheral blood lymphocytes cells (PBL). Acid extracts promoted to reduce HeLa cells and to grow PBL cells. At high concentrations, acid extracts showed the highest APTT and TT clotting time. Antitumoral and anticoagulant activities of ulvans from Ulva lactuca promote their use as effective therapeutic agent.

Effect of extraction methods on the physicochemical, structural, functional, and antioxidant properties of the dietary fiber concentrates from male date palm flowers.

The current study evaluates the effect of both aqueous and alkaline extraction methods on the physicochemical, structural, functional, and antioxidant properties of dietary fibers (DF) from male date palm flowers (MDPF). The DF extracted by the alkali treatment (ADF) display a higher DF content as well as lower protein and lipid content than the DF resulting from watery extraction (WDF). The scanning electron microscopy, the Fourier-transform infrared spectroscopy, and the X-ray diffraction show that the alkaline treatment contributes to a slight modification of the structural characteristics of ADF leading to better purity and functional properties. The oil holding capacity and the antioxidant activity of ADF have improved compared to the WDF, which makes this concentrate a promoting functional ingredient and a natural antioxidant. Therefore, these findings confirm the wealth of both concentrates in DF, especially ADF, as well as their potential of functional and antioxidant properties, which emphasize their suitability to be used in food applications as functional ingredients. PRACTICAL APPLICATIONS: Nowadays, studies on the extraction of DF from vegetable waste are of considerable interest in the face of the rising global demand for dietetic food. The male date palm flowers (MDPF), an agricultural waste generated during the period of pollination, are valuable natural sources of DF and antioxidants. The insoluble DF of MDPF could be essential in a balanced diet as they could fight against obesity by creating a feeling of satiety. The presence of antioxidants, which are known for preventing or slowing cell damage caused by free radicals, could contribute to the improvement of the antioxidant properties of the formulated food. The functional properties of DF concentrates from MDPF are able to solve the technical problems of agri-food industries when used as food ingredients. The use of DF from MDPF, consequently, contributes to the minimization of waste and provides value addition to the by-product considered as waste in agricultural processing.

Smart ulvan films responsive to stimuli of plasticizer and extraction condition in physico-chemical, optical, barrier and mechanical properties.

Smart films were produced with ulvan extracted from the green seaweed Ulva. lactuca at different extraction conditions, by varying the glycerol or sorbitol in specific plasticizer concentration. Chemical composition and molecular weight characteristics of ulvans were carried out by GLC and HPSEC analysis, respectively. Regardless of the extraction procedure, the investigation revealed that ulvans were selected as reproducible and suitable materials of stimuli-responsive due to its peculiar chemical composition and self-aggregation molecular behavior. When using the terminology of stimuli-responsive system, we declare that the physico-chemical, barrier, optical, and mechanical characteristics of ulvan films system are strongly responsive to extraction conditions and to plasticizer type and concentration. As plasticizer concentration increased, thickness, moisture content (MC), water solubility, water vapor permeability (WVP), transparency, elongation at break (EAB), usually UV and visible light protection of ulvan films increased, while, their tensile strength (TS) decreased significantly. The films prepared with glycerol exhibited better solubility, transparency and mechanical properties, than those with sorbitol. However, the films formed with sorbitol had the greatest moisture resistance and more effective vapor, visible and UV light barrier as well as the lowest solubility. The FTIR spectra evidenced the expected outcome of the chemical interaction and miscibility kind between polysaccharides and plasticizers.

Influence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products.

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter) - 1 of commercial fibrolytic enzymes (MAXFIBER-I ® , SHAUMANN GmbH, Wahlstedt, Germany) on in vitro fermentation of date palm (Phoenix dactylifera) by-products: date kernels, wasted dates, floral stems, and palm fronds. Rumen contents were obtained from two non-lactating Holstein cows. Enzyme supplementation to by-products was carried out 12 h prior to incubation. Compared to the control, the enzymatic supplementation quadratically increased the extent but not the gas production rate of date kernel fermentation. Indeed, the potential gas production increased notably by 14.8 % with the lowest enzymes dose following recorded gas production after 48, 72, and 96 h of incubation. The estimated organic-matter digestibility, metabolisable energy, and total volatile fatty acids in the incubation fluid tended to be increased with the lowest dose by 7.8 %, 8.4 %, and 13.9 % respectively. For the wasted dates, this feed additive tended to linearly increase the gas production rate of fermentation with the highest dose. On the other hand, this supplementation had no effect on the ruminal fermentation of the floral stems and palm fronds. The exogenous fibrolytic enzymes were more effective on fibrous but not on lignified date palm by-products.

Effects of extraction procedures and plasticizer concentration on the optical, thermal, structural and antioxidant properties of novel ulvan films.

Active films were produced with sulphated polysaccharides "ulvan", extracted from the green seaweed Ulva lactuca with different extraction procedures, by varying the glycerol or sorbitol plasticizer concentration at 1% and 2% (w/v). The surface charge and glass transition temperature (Tg) of ulvans were carried out by zeta (ζ)-potential and DSC analysis, respectively. The investigation revealed that ulvans were anionic stable polymers and they had great Tg values. Regardless of the extraction procedure, ulvans can give successful films formulations. However, the optical, thermal, structural and antioxidant characteristics of ulvan films were strongly affected by extraction conditions and by the variation of the type and concentration of plasticizer. In general, as plasticizer concentration increased, ferrous chelating activity and compact structure increased as well, while, Tg, lightness and DPPH radical-scavenging activity decreased. Interestingly, the films plasticized with glycerol exhibited better compact structure, more negative temperature of transition, and greater free radical scavenging ability than with sorbitol. However, the films prepared with sorbitol had the highest L* values and chelating ability. The current study revealed a high correlation between zeta (ζ)-potential of ulvans and their Tg (R2 = 0.98), as well as with scavenging activity of ulvan films (R2 = 0.8-0.99).

Physicochemical properties of water-soluble polysaccharides from black cumin seeds.

In the present work, water-soluble polysaccharides were isolated from black cumin seeds. Polysaccharides were characterized by their carbohydrate composition, molecular weight, thermal stability and by FTIR, NMR spectroscopy and X-ray diffraction. The surface, the functional and the antioxidant properties of black cumin water-soluble polysaccharides (BCWSP) were also investigated. BCWSP consisted mainly of galacturonic acid (30.20%), glucuronic acid (17.66%) and neutral sugar (22.99%). BCWSP was composed of high peak molecular weight. The FTIR spectrum obtained for BCWSP showed two most important absorptions, at 1659 and 1085 cm-1, which corresponded to COO- of uronic acids and pyranose form, respectively. NMR spectroscopy data suggested that the BCWSP is probably a rhamnogalacturonan backbone with galactan and arabinan side chains. X-ray pattern revealed the semi-crystalline behavior of BCWSP. WHC and OHC of BCWSP were relatively high and varied with temperatures. The polysaccharide zeta potential was greatly affected by pH. Results indicated that the decrease of surface tension has influenced foaming and emulsifying capacities. The DPPH radical scavenging activity of the BCWSP was 63.25% at 1 mg/mL. The BCWSP displayed moderate reductive, ß carotene bleaching and chelating abilities. Overall, our results suggested that BCWSP could be used as alternative additives in food and non-food products.

Effect of substituted gelling agents from pomegranate peel on colour, textural and sensory properties of pomegranate jam.

A series of pomegranate jams were prepared from a Tunisian ecotype (Tounsi) with different amounts of sugar (10, 20 and 30%) and low-methoxylated pectin (0.2, 0.7 and 1.2%). The most appreciated formulation was that contaning 30% sugars and 0.2% pectin. Then, commercial pectin was substituted by other gelling agents (pomegranate peel powders dried at 50°C vs lyophilized, pectin and fibre extracted from pomegranate peel) for the preparation of pomegranate peel-based jams. The elaborated jams were evaluated for physichochemical, colour, texture and sensory characteristics. Results revealed that the jam (JPP2) elaborated with 0.2% pectin extracted from pomegranate peel exhibited similar overall acceptability to that prepared with commercial pectin. However, it was more acceptable than other pomegranate peel-based jams, which was related to a better appreciation of sweetness and colour. According to the colour and texture measurements, this sample (JPP2) was more reddish and less firm than other samples.

Antioxidant properties and phenolic profile characterization by LC-MS/MS of selected Tunisian pomegranate peels.

Antioxidant contents and activities of different extracts from four Tunisian pomegranate peels, locally called "Acide", "Gabsi", "Nebli" and "Tounsi", were studied. Peels samples were extracted with three solvents (water, ethanol and acetone). For each extract, the total phenol contents and antioxidant activity were evaluated. The highest values of polyphenol, tannins, flavonoids and anthocyanins were recorded in the acetone extract of Acide ecotype with 304.6 mg gallic acid equivalent/g; 292.23 mg gallic acid equivalent/g; 15.46 mg Quercetin/g and 54.51 mg cy-3-glu/100 g, respectively. The acetone extract of Acide ecotype also showed the highest free radical-scavenging and reducing power activity compared to other extracts. Besides, the phytochemical analysis by LC-MS/MS revealed a high content of ellagitannins with punicalagin and punicalagin derivatives as the major compounds that might be responsible for promising antioxidant activity of pomegranate peel extracts. Two compounds (Castalagin derivative and Galloyl-bis-HHDP-hex derivative) were detected only in "Acide" ecotype in important contents.

Technological properties of milk gels produced by chymosin and wild cardoon rennet optimized by response surface methodology.

The aim of this paper was to optimize extraction conditions of C. cardunculus rennet by response surface methodology, in order to maximize its milk-clotting activity (MCA). The second objective was to examine the effect of different amounts of the optimized extract and the type of milk, on technological characteristics of the obtained gels. Results of the central composite design showed that the optimum extraction conditions, corresponding to maximum MCA (9.550CAU/mL), were selected as follows: Grinding time 30s, pH 3, extraction time 50min and solid to liquid ratio 15g/100mL. According to technological properties, it can be concluded that C. cardunculus extract exhibited an excellent efficiency on raw milk, in term of dynamic moduli and gel firmness, as compared to chymosin. A good gelation time and WHC were also obtained. Consequently, the optimized C. cardunculus rennet has the potential to be employed as an efficient milk-clotting agent.

Effect of extraction procedures on structural, thermal and antioxidant properties of ulvan from Ulva lactuca collected in Monastir coast.

The present work aims to evaluate the effect of an acid extraction as well as a combined enzymatic-chemical extraction on structural, thermal and antioxidant properties of the sulphated polysaccharide 'ulvan' from the green seaweed Ulva lactuca. Structural characterization by FTIR and NMR spectroscopies showed the typical peaks of ulvan, namely, uronic acids, rhamnose and sulphate. FTIR analysis revealed that the extraction procedures were able to maintain ulvan structure. Despite differences in the extraction procedures, 13C NMR spectra were globally similar, proving a comparable chemical structure of ulvans. A major difference has been observed in signal intensity which reflected the resonance of glucose or xylose. Thermal characterization proved that ulvans were thermally stable until approximately 180°C. Antioxidant properties of ulvans were evaluated in vitro through different antioxidant assays. Ulvan, which is extracted at pH 1.5 and 90°C, exhibited the greatest scavenging activity (IC50=13.56µg/ml) towards DPPH radical. Result indicated that Mw has influenced inhibitory effect on DPPH radical of ulvan. The current study revealed also a high correlation between sulphate contents of ulvans and their reducing power (R2=-0.89) and their metal scavenging activity (R2=0.97). Overall, ulvans have peculiar structural, thermal and antioxidant properties which promote their use in food or pharmaceutical products as natural ingredient.

Anaplasma phagocytophilum in horses and ticks in Tunisia.

BACKGROUND: Anaplasma phagocytophilum , the causative agent of granulocytic anaplasmosis, affects several species of wild and domesticated mammals, including horses. We used direct and indirect methods to compare and evaluate exposure to A. phagocytophilum in horses in northern Tunisia. METHODS: Serum from 60 horses was tested by IFA for antibodies to A. phagocytophilum , and whole blood was tested for A. phagocytophilum 16S rRNA gene using a nested-PCR. To examine the risk of A. phagocytophilum transmission, 154 ticks that had been collected from horses were examined for the presence of A. phagocytophilum by nested-PCR targeting 16S rRNA gene. RESULTS: This is the first time that A. phagocytophilum has been detected in horses in Tunisia, with an overall seroprevalence of 40/60 (67%). Six of the seroreactive samples (10%) had an IFA titer of 1:80, 14 (23%) of 1:160, 8 (13%) of 1:320 and 12 (20%) a titer 1 ≥ 640. The seroprevalence revealed no significant regional and sex differences. In contrast, a significant difference was observed between breeds. Eight (13%) of the horses were positive for A. phagocytophilum in the PCR, with no significant breed and age differences. Hyalomma marginatum was a predominant tick species (130/154), and 3 were infected by A. phagocytophilum (a prevalence of 2.3%). The concordance rate of A. phagocytophilum detection between IFA and PCR had a k value of -0.07. CONCLUSIONS: The results presented in this study suggest that horses infested by ticks in Tunisia are exposed to A. phagocytophilum.