Moringa, Milk Thistle, and Jujube Seed Cold-Pressed Oils: Characteristic Profiles, Thermal Properties, and Oxidative Stability.

Cold-pressed moringa, milk thistle, and jujube seed oils were investigated in terms of their characteristic profiles, thermal properties, and oxidative stability. The findings proved that the extracted oils were characterized by high nutritional values, which encourages their use in various fields. Results showed significant differences between the obtained oils. Overall, jujube seed oil exhibited the best quality parameters, with acidity equal to 0.762 versus 1% for the moringa and milk thistle seed oils. Milk thistle seed oil showed absorbance in the UV-C (100-290 nm), UV-B (290-320 nm), and UV-A (320-400 nm) ranges, while the moringa and jujube seed oils showed absorbance only in the UV-B and UV-A ranges. Concerning bioactive compounds, jujube seed oil presented the highest content of polyphenols, which promoted a good scavenging capacity (90% at 10 µg/mL) compared to the moringa and milk thistle seed oils. Assessing the thermal properties of the obtained oils showed the presence of four groups of triglycerides in the moringa and milk thistle seed oils, and two groups of triglycerides in the jujube seed oil. The thermograms were constant at temperatures above 10 °C for milk thistle seed oil, 15 °C for jujube seed oil, and 30 °C for moringa seed oil, which corresponded to complete liquefaction of the oils. The extinction coefficients K232 and K270, monitored during storage for 60 days at 60 °C, proved that jujube seed oil had the highest polyphenols content and was the most stable against thermal oxidation.

Cynara cardunculus as a potential source of milk coagulating protease: Effects on physical properties of cow's milk.

In the present research study, Cynara cardunculus (wild cardoon) flowers were blended and extracted using different types of buffers (phosphate buffer; citrate buffer and distilled water) for different maceration times. The most reliable, quick and efficient buffer was found to be phosphate (pH = 6.5) with a 6-h maceration time, which was used throughout this study. C. cardunculus extract (CE) was found to have high clotting and proteolytic activities. The extracted enzyme was found to be very stable against a wide range of pH values as well as of temperature. The formation of milk gels prepared in the presence of CE with different types of milk was evaluated using dynamic rheology and Turbiscan. The evolution of both elastic (G') and viscous (G″) moduli was monitored with time. The values of the whole milk enriched with milk powder gels were higher. Coagulum stability was evaluated using Turbiscan. The textural properties and the curd-firming rate of coagulum were also determined. In conclusion, the prepared CE could be an efficient milk-clotting agent in the production of dairy products.

Date, Apple, and Pear By-Products as Functional Ingredients in Pasta: Cooking Quality Attributes and Physicochemical, Rheological, and Sensorial Properties.

This study aims to evaluate the impact of incorporating pear, date, and apple by-products on pasta properties. Pasta properties including cooking quality, texture, color, rheology, thermal gelling, and microstructural characteristics were evaluated. Common wheat flour was substituted by 0, 2.5, 5, 7, and 10 g/100 g of by-products. To choose the best-suited substitute of flour for the preparation of pasta, the sensorial properties of pasta were investigated. Interrelationships between all the physicochemical parameters were investigated using multiple factor analysis. We also studied the impact of storage (7, 15, and 30 days) on the physicochemical proprieties of pasta. The results revealed that the chemical composition of pasta elaborated with by-products was characterized by higher energy (~386 Kcal) and fiber content (~13%) than the control pasta. Generally, materials added to the durum wheat pasta reduce optimum cooking time, adhesiveness, and extensibility, and enhance the swelling index, cooking loss, cooking water absorption, water activity, firmness, and tenacity of pasta. Cooked pasta samples were significantly (p < 0.05) darker (L*) and greener (-a*) than the control pasta. Increasing the rate of by-products from 2.5% to 10% principally altered the texture and structure of pasta. Scanning electron microscopy analysis showed that the inclusion of by-products into pasta leads to a disruption of the protein matrix. A practical formulation (2.5% of by-products) can be selected, since a significant difference was detected between overall acceptability scores. Grouping the variables in the principal component analysis plot showed that pasta samples can be divided into three groups. Each group was correlated by a specific variable. A significant modification of the physical parameters of pasta was observed after 30 days of storage.

Development and characterization of chitosan films carrying Artemisia campestris antioxidants for potential use as active food packaging materials.

Active food packaging films based on chitosan and enriched with Artemisia campestris hydroalcoholic extract (ACHE), aqueous extract (ACAE) and essential oil (ACEO) were developed. The effects of incorporating A. campestris were investigated on the physical, mechanical, thermal and antioxidant characteristics of the films. The structural properties of the films were evaluated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that adding ACHE and ACEO improved the water resistance of chitosan films. The FTIR spectroscopy analysis revealed covalent interaction and hydrogen bonding between chitosan and ACHE. The XRD and SEM analyses indicated that interactions occurred between the film matrix and A. campestris active compounds, which could be reflected by the physical and mechanical properties of composite films. Incorporating ACHE and ACAE in the chitosan matrix decreased the tensile strength. The film extensibility was reduced when ACHE and ACEO were added. All films exhibited great thermal stability as the degradation occurred above 300 °C. The addition of A. campestris active compounds, particularly extracts, to chitosan films notably increased the antioxidant and UV-Vis barrier properties. Chitosan films enriched with the A. campestris antioxidant compounds could be applied as food packaging alternatives.

Effect of brine concentration on physico-chemical characteristics, texture, rheological properties and proteolysis level of cheeses produced by an optimized wild cardoon rennet.

The main objective of this study was to test the efficiency of a wild cardoon (Cynara cardunculus L.) rennet, previously optimized by response surface methodology, in cheese making process; then to select the best brine concentration, leading to excellent cheese quality. Results showed that the optimized C. cardunculus rennet and chymosin produced curds with similar properties (yield, colour, texture, viscoelasticity), suggesting that this coagulant could replace successfully calf rennet. After brining at different salt concentrations (5, 7, 10 and 15%), we concluded that the use of 15% of salt in brine was an efficient way to reduce considerably the proteolysis level in C. cardunculus cheeses, stored for 28 d at 4 °C. At this salt level, the highest hardness, gumminess, viscoelasticity and yield of soft cheeses were also recorded. In conclusion, the satisfactory findings could open new opportunities to produce industrially the optimized C. cardunculus rennet and its cheeses in the Mediterranean area.

Effect of succinylation on the secondary structures, surface, and thermal properties of date palm pollen protein concentrate.

The present study was attempted to investigate the effect of succinylation, as chemical modification, on the functionality of male date palm pollen protein concentrate (MDPPPC). Succinylation was applied at two levels, 4 and 8 mol of succinic acid per mole of lysine. 4 M and 8 M were compared to the native MDPPPC. Findings proved that succinylation improved the surface properties of pollen protein including solubility and surfactant activity. Increased solubility of succinylated MDPPPC has been noticed especially in pH superior to pHi. The results from the differential scanning calorimetry showed a significant decrease (P < 0.05) of the denaturation temperature and the heat enthalpy for succinylated MDPPPC. ß turn of succinylated MDPPPC increased significantly (P < 0.05) at the expense of ß sheet indicating that the protein gained more mobility after succinylation which explains the enhancement of the functional properties and promotes the use of succinylated protein as a techno-functional ingredient.

Rheological and emulsifying properties of an exopolysaccharide produced by potential probiotic Leuconostoc citreum-BMS strain.

EPS-BMS, is to our knowledge, the first high molecular weight exopolysaccharide from potential probiotic Leuconostoc citreum-BMS strain that consists on a mixture of α-(1,6)-dextran branched at the third position and ß-(2,6)-levan. This sample exhibited interesting rheological and emulsifying properties under different conditions. Steady shear experiments proved that EPS-BMS had a pseudoplastic behavior without thixotropic properties. Interestingly, pseudoplasticity was maintained even under stress conditions of temperature, pH and salts, which could provide some sensory properties for food products such as mouth feel. Dynamic oscillatory measurements reflected a liquid-like behavior of the sample regardless of the studied EPS concentration, pH, temperature and ionic force. Results related to the emulsifying as well as interfacial properties showed that EPS-BMS had great potential to be applied as emulsifier and/or emulsion stabilizer in both neutral and acidic conditions. Based on the properties reported in this work, EPS-BMS could be potentially applied in the food industry.

Optimization of acorn (Quercus suber L.) muffin formulations: Effect of using hydrocolloids by a mixture design approach.

Acorn flour was used as a gluten-free ingredient to produce acorn muffins. Interaction effects between xanthan (X), carboxymethyl cellulose (CMC) and κ-carrageenan (κ-C) (0-0.3%) on the height and textural parameters of the formulated acorn flour muffins were investigated using a mixture design approach. Each studied parameter was optimized individually. Then, an optimal formulation giving a product with characteristics as close as possible to those of a wheat flour muffin sample was determined. Results revealed that addition of each hydrocolloid separately, or their ternary combination improved the muffin height. Optimal height value was predicted to reach 3.96 cm when using 26.8% X, 50.5% CMC and 22.7% κ-C. As regard to textural parameters (firmness, cohesiveness, springiness and adhesiveness), presence of the three hydrocolloids had an antagonistic effect. The best hydrocolloids mixture giving optimal height (3.92 cm), firmness (3.19 N) and adhesiveness (0.66 N) was that containing 20.5% X and 79.5% CMC.

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.

Toward the enhancement of sensory profile of sausage "Merguez" with chickpea protein concentrate.

The influence of different Chickpea Protein Concentrates (CPC) addition at different levels (CPC: 1.5, 2.5 and 5% (w/w)) on physico-chemical, textural and hedonic properties of formulated and cooked sausage "Merguez" were investigated. The obtained results exhibited that CPC addition increased protein content of "Merguez" sausage and improved the process yield. Significant differences were noticed on the cooking loss and textural properties for "Merguez" sausages formulated with 5% of CPC compared to the control (p < 0.05). Hedonic analysis showed that protein addition had no significant effect on sausages taste. However, sausage texture and global acceptability were markedly improved (p < 0.05). These results suggest that CPC could be an important alternative source of protein additive for the improvement of the physico-chemical, textural and sensorial properties of meat sausages.

Ultrafiltration and thermal processing effects on Maillard reaction products and biological properties of date palm sap syrups (Phoenix dactylifera L.).

The effect of ultrafiltration process and temperature concentration on MRPs content and antioxidant, antimicrobial and cytotoxic properties of date palm sap syrups were investigated. MRPs were analyzed by HPLC. Antioxidant activity was evaluated by reducing power and DPPH free radical and H2O2 scavenging activities. Antimicrobial activity was evaluated by the agar disk diffusion method. In vitro cytotoxic activity was examined by cell proliferation assay. Date sap syrups displayed strong antioxidant activities which are correlated 5HMF and 2F contents. In addition, concentration at 100 °C, unlike ultrafiltration process, enhanced significantly the antioxidant activities sap syrups and total phenolic contents. The antimicrobial activities showed marked activity against S. enterica, P. aeruginosa, S. aureus, L. monocytogenes with an inhibition zone of 21, 34, 27 and 34 mm respectively. Cytotoxicity assays showed that sap syrups can inhibit the proliferation of HeLa cell lines at high concentration.

Identification and molecular docking of novel ACE inhibitory peptides from protein hydrolysates of shrimp waste.

The effect of enzymatic hydrolysis by Savinase on the interfacial properties and antihypertensive activity of shrimp waste proteins was evaluated. The physicochemical characterization, interfacial tension, and surface characteristics of shrimp waste protein hydrolysates (SWPH) using different enzyme/substrate (E/S) (SWPH5 (SWPH using E/S = 5), SWPH15 (SWPH using E/S = 15), and SWPH40 (SWPH using E/S = 40)) were also studied. SWPH5, SWPH15, and SWPH40 had an isoelectric pH around 2.07, 2.17, and 2.54 respectively. SWPH5 exhibited the lowest interfacial tension (68.96 mN/m) followed by SWPH15 (69.36 mN/m) and SWPH40 (70.29 mN/m). The in vitro ACE inhibitory activity of shrimp waste protein hydrolysates showed that the most active hydrolysate was obtained using an enzyme/substrate of 15 U/mg (SWPH15). SWPH15 had a lower IC50 value (2.17 mg/mL) than that of SWPH5 and SWPH40 (3.65 and 5.7 mg/mL, respectively). This hydrolysate was then purified and characterized. Fraction F1 separated by Sephadex G25 column which presents the best ACE inhibition activity was then separated by reversed-phase high performance liquid chromatography. Four ACE inhibitory peptides were identified and their molecular masses and amino acid sequences were determined using ESI-MS and ESI-MS/MS, respectively. The structures of the most potent peptides were SSSKAKKMP, HGEGGRSTHE, WLGHGGRPDHE, and WRMDIDGDIMISEQEAHQR. The structural modeling of anti-ACE peptides from shrimp waste through docking simulations results showed that these peptides bound to ACE with high affinity.

Influence of the ripening stage and the lyophilization of wild cardoon flowers on their chemical composition, enzymatic activities of extracts and technological properties of cheese curds.

The selection of an appropriate Cynara cardunculus flowers batch is a preliminary step to produce rennet with better clotting properties. For this reason, we proposed to study the influence of the ripening stage and the lyophilization of cardoon flowers on their chemical composition, enzymatic activities of extracts, and technological properties of cheese curds. Results of flowers composition have shown that lyophilized flowers harvested at the middle of ripening stage (A) could be employed to produce mainly proteins or milk-clotting proteases. To confirm this, enzymatic activities of extracts and technological properties of curds were assessed. The experimental findings revealed that flowers lyophilization seems to be an efficient way to produce rennet with better clotting properties, leading to higher yield, moisture, and texture parameters of curd. These findings allowed us to select lyophilized flowers (A) for further cheese making process.

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.

The addition effect of Tunisian date seed fibers on the quality of chocolate spreads.

Novel chocolate spreads were enriched by soluble and insoluble dietary fibers from Tunisian Deglet Nour date seeds at 1, 2, 3, 4, and 5% levels in the conventional chocolate spread. Defatted Deglet Nour date seeds, date seed soluble fiber concentrate (DSSFC) and date seed insoluble fiber concentrate (DSIFC) were characterized by high levels of dietary fibers (80-90%). Chocolate spread enriched with 5% of DSSFC presented the highest oil binding capacity (304.62%) compared to the control (102%). Whatever the DSIFC and DSSFC incorporation levels, no significant difference was recorded between the firmness, chewiness, and adhesiveness of prepared chocolate spreads compared to the control (p < .05). Sensory evaluation revealed that all prepared chocolate spreads enriched by DSIFC and DSSFC were accepted by panelists. These results indicated the value of date seeds as new source of dietary fibers to develop chocolate spread and could also improve health benefits and functional properties. PARACTICAL APPLICATION: Tunisia is considered to be one of the dates-producing countries. The mean annual yield of date fruits is about 200,000 tons. From this, around 20,000 tons of date seeds could be collected. This by-product of date processing industries could be regarded as an excellent source of dietary fiber with interesting technological functionality and many beneficial effects on human health. Then, date seeds could present a value addition by extraction and use of date seed fiber concentrate in chocolate spread formulation.

Effect of extraction pH on techno-functional properties of crude extracts from wild cardoon (Cynara cardunculus L.) flowers.

In the present paper, techno-functional properties of rennet derived from C. cardunculus, prepared at various pH (from 3 to 6), were investigated. It was found that the extract prepared at pH 3 had the best milk-clotting properties (MCA/PA ratio). It presented also the highest enzyme content, determined by densitometry analysis on 1D and 2D gels electrophoresis. Formation of milk gels produced by the extracts and chymosin was monitored using dynamic rheology and turbiscan. It can be assumed that by lowering rennet pH, milk pH decreases, causing a significant increase of curd firmness and both elastic (G') and viscous (G″) moduli. Results obtained by turbiscan showed similar ΔBS values of gels produced, after 2h, by chymosin and the crude extract at pH 3. In conclusion, C. cardunculus extract prepared at low pH has the potential to be employed as an efficient milk-clotting agent in the production of dairy products.

Identification of proteins from wild cardoon flowers (Cynara cardunculus L.) by a proteomic approach.

Proteomic approach was applied to identify total proteins, particularly the enzymatic content, from wild cardoon flowers. As the selection of an appropriate sample preparation method is the key for getting reliable results, two different extraction/precipitation methods (trichloroacetic acid and phenol/ammonium acetate) were tested on fresh and lyophilized flowers. After two-dimensional electrophoresis (2D-E) separations, a better protein pattern was obtained after phenol extraction from lyophilized flowers. Only 46 % of the total analyzed spots resulted in a protein identification by mass spectrometry MALDI-TOF. Four proteases (cardosins A, E, G, and H), which have become a subject of great interest in dairy technology, were identified. They presented molecular weights and isoelectric points very close and high levels of homology between matched peptides sequences. The absence of the other cardosins (B, C, D, and F) could be an advantage, as it reduces the excessive proteolytic activity that causes bitter flavors and texture defects, during cheese making.

Pea and Broad Bean Pods as a Natural Source of Dietary Fiber: The Impact on Texture and Sensory Properties of Cake.

Attention has focused on bakery products such as cake which is one of the most common bakery products consumed by people in the world. Legume by-products, pea pods (PPs) (Pisum sativum L.) and broad bean pods (BBPs) (Vicia faba L.) mediterranean (Tunisian), has been studied for its high dietary fiber content (PP: 43.87 g/100 g; BBP: 53.01 g/100 g). Protein content was also a considerable component for both by-products. We investigated the effect of substituted of 5%, 10%, 15%, 20%, 25%, and 30% of PP and BBP flours on the sensory and technological properties in cake. Cakes hardness increased whereas L* and a* color values decreased. The overall acceptability rate showed that a maximum of 15% of PP and BBP flours can be added to prepare acceptable quality cakes.

Synergistic effect of Aspergillus tubingensis CTM 507 glucose oxidase in presence of ascorbic acid and alpha amylase on dough properties, baking quality and shelf life of bread.

The impact of Aspergillus tubingensis glucose oxidase (GOD) in combination with α-amylase and ascorbic acid on dough properties, qualities and shelf life of bread was investigated. Regression models of alveograph and texture parameters of dough and bread were adjusted. Indeed, the mixture of GOD (44 %) and ascorbic acid (56 %) on flour containing basal improver showed its potential as a corrective action to get better functional and rheological properties of dough and bread texture. Furthermore, wheat flour containing basal additives and enriched with GOD (63.8 %), ascorbic acid (32 %) and α- amylase (4.2 %) led to high technological bread making parameters, to decrease the crumb firmness and chewiness and to improve elasticity, adhesion, cohesion and specific volume of bread. In addition to that, the optimized formulation addition significantly reduced water activity and therefore decreased bread susceptibility to microbial spoilage. These findings demonstrated that GOD could partially substitute not only ascorbic acid but also α-amylase. The generated models allowed to predict the behavior of wheat flour containing additives in the range of values tested and to define the additives formula that led to desired rheological and baking qualities of dough. This fact provides new perspectives to compensate flour quality deficiencies at the moment of selecting raw materials and technological parameters reducing the production costs and facilitating gluten free products development. Graphical abstractᅟ.