Oral communications

AO-16: Study of Camel Milk Coagulation Induced by Cardosins: Enzymes Purified from Wild Cardoon Flowers

Thu, 05 Oct 2023 00:00:00 GMT

AO-16: Study of Camel Milk Coagulation Induced by Cardosins: Enzymes Purified from Wild Cardoon Flowers ZIKIOU, Abdellah; SACI, Fairouz; FIALA, Samah; HADJADJ, Nasreddine Subject description: Camel milk transformation poses significant challenges due to its unique composition and perceived difficulties in coagulation. This research explores the feasibility of coagulating camel milk using proteases derived from wild cardoon flowers, Cynara cardunculus Var. sylvestris. Objectives: The primary objective of this study is to investigate the potential of cardoon flower proteases for coagulating camel milk and compare their performance to a recombinant chymosin enzyme designed specifically for camel milk coagulation. Methods: Our methodology consisted of several key steps. Initially, cardosins were extracted, purified, and characterized using chromatographic and electrophoretic techniques. Subsequently, we measured their coagulating and proteolytic activities, cheese yields, and syneresis ability using camel milk as the substrate. Additionally, we assessed the textural properties of the coagulums obtained with the Optigraph by measuring firmness parameters (A20, A30, A40) and coagulation velocity (R and OK20). The study was conducted by comparing the cardoon-derived proteases with a commercially available recombinant enzyme developed specifically for camel milk coagulation. Results and discussion: Our purification protocol allowed us to obtain three types of cardosins: Cardosins A0, A, and B. All three are heterodimeric proteins composed of two chains, large and small, with molecular weights ranging from 42 to 36 kDa for the large chains and 16 to 13 kDa for the small chains. The analysis of coagulation properties and theoretical cheese yields demonstrated that the purified cardosins exhibit promising coagulation potential for camel milk. Cardosins A and B displayed activities similar to those of the commercial recombinant chymosin (23 ± 2 IUMC and 21 ± 1 for cardosins A and B, respectively, compared to 25 ± 2 for the commercial enzyme). However, cardosin A0 exhibited lower activity (9 ± 2 IUMC). Regarding textural properties assessed with the Optigraph, no significant differences were observed between cardosins A and B and the commercial enzyme, whereas cardosin A0 generated a friable and less firm coagulum. Conclusion: Based on these findings, we believe that proteases from cardoon flowers can be applied as coagulation agents for camel milk transformation into cheese. The cardoon-derived proteases, particularly cardosins A and B, exhibit coagulation capabilities comparable to those of the commercially available recombinant chymosin. This research contributes to the potential development of more sustainable and cost-effective methods for camel milk processing in the cheese industry

AO-15: Comparative study of the chemical and biological aspects of spend coffee grounds recovered by the filtration and decoction methods

Thu, 05 Oct 2023 00:00:00 GMT

AO-15: Comparative study of the chemical and biological aspects of spend coffee grounds recovered by the filtration and decoction methods TENIOU, Fatima El Batoul; AGGOUN, Moufida; BENAHMED, Chaima; BELKHAIRI, Chahinez; AMOKRANE, Serine; BENSOUICI, Chawki; ARHAB, Rabah Subject description: Two types of coffee grounds has been studied; the first type was extracted by pressure, while the second was obtained by decoction. Objectives: The aim of our work is to compare the recovered ground using these two methods on both, chemical and biological scales. Methods: The chemical study concerns primary compounds (dry, mineral and fatty matter) and secondary compounds (phenols, flavonoïds), the biological study however, is about assessing the antioxidant potential (DPPH, CUPRAC, FRAP, Phenanthroline) as well as the enzymatic one (Anti Alzheimer’s and Anti-diabetic) of the two samples. For valuation purposes, and by choosing the most active coffee ground, we simultaneously elaborate the effect of the preparation method on the quality of the recovered coffee ground. Results and discussion: The results show a difference between the two extracts in the primary composition (DM, MM, FM) and a similarity in the secondary composition for phenols and flavonoids’ levels. The evaluation of the antioxidant activity shows that the two extracts have a low and similar antioxidant potential; and that both had no activity against Alzheimer's disease. In return, the two substrates possess a detectable activity against the therapeutic enzyme responsible for the development of diabetes. Conclusion: Espresso coffee grounds seem to be richer in fat source than decoction grounds. Therefore, the two beverage preparation methods discussed herein did not greatly influence the quality of the coffee grounds. In addition, given its phenolic and chemical composition, the coffee ground presents an important source of natural compounds of biological and therapeutic interest

AO-14: Insects oil a promising ingredient for cosmetic formulations: Fatty acid profile, antioxidant and antibacterial activity of pressed Locusta migratoria oil

Thu, 05 Oct 2023 00:00:00 GMT

AO-14: Insects oil a promising ingredient for cosmetic formulations: Fatty acid profile, antioxidant and antibacterial activity of pressed Locusta migratoria oil TEBIB, Nacira; ACHEUK, Fatma Subject description: Edible insects represent an interesting alternative source of proteins and lipids for human and animal consumption and have the potential to play a significant role in a circular economy to meet current societal challenges. There is growing interest in the use of insects in the manufacture of biomaterials and the valorization of secondary waste products. Objectives: The potential of locust (Locusta migratoria) oil, adapted to intensive breeding using by-products as feed, for incorporation as an ingredient in cosmetic formulations is investigated. Methods: Locusts are mass-reared under controlled conditions. Firstly, techniques for obtaining good oil extraction yields from dried locust biomass were tested. Extraction using hexane as a solvent (soxhlet) and traditional pressing. Fatty acid composition (%) and profile (%) and the major groups of fatty acids of the migratory locust were determined (gas chromatography-mass spectrometry (GC-MS)). For antioxidant capacity, two different methodologies were used (DPPH, FRAP), and agar diffusion tests were performed for antibacterial activity. Results and discussion: Migratory locust is rich in lipids (≈33% of dry weight), and traditional pressing was found to be the best system for maximizing oil yield (26.90g/100g vs. 24.75g/100g for hexane). The most abundant saturated fatty acid was palmitic acid, 16:0 (30.5%) followed by stearic acid, 18:0 (9.3%TFA), while oleic acid, C18:1n9c (40.53%), was the main monounsaturated fatty acid, and linolenic acid, C18:3n3 (13.7%) was the most abundant polyunsaturated fatty acid. Unsaturated fatty acids (UFAs) make up 59% of TFA. MUFA are the most predominant fatty acids in locust tissues, accounting for 41.2% of TFA, followed by SFA, which make up 41% of TFAs, and PUFA, which make up 17.8% of TFA. The proportion of saturated/unsaturated fatty acids was (0.7). Omega-6 content was (11.5mg/g) and omega-3 (24.8mg/g), representing (5.6% TFA) and (12.1% TFA). The N-3/N-6 ratio was 2.2. Regarding antioxidant activity, Locusta migratoria showed values of 2.03, and 4.93 mg TE/g of oil for DPPH and FRAP tests. Interestingly, agar diffusion tests demonstrated the sensitivity of Gram positive Bacillus subtilis and Staphylococcus aureus to the oil, while the growth of Gram-negative Pseudomonas aeruginosa and Escherichia coli was unaffected. This study confirms that fat and other active compounds in pressed oil could be effective antimicrobials against bacteria. Conclusion: The fatty acid profile indicates a high proportion of unsaturated fatty acids, and the antioxidant and antibacterial activity of pressed Locusta migratoria oil is promising for use in cosmetic applications

AO-13: Phenolic Compounds of algae (Ulva lactuca): Optimization of extraction by response surface methodology and in vitro antioxidant properties

Thu, 05 Oct 2023 00:00:00 GMT

AO-13: Phenolic Compounds of algae (Ulva lactuca): Optimization of extraction by response surface methodology and in vitro antioxidant properties CAID, Rachida; CHAALAL, Makhlouf; YDJEDD, Siham; CHEBOUT, Afaf; LAOUABDIA SELLAMI, Nadjette1 Subject description: Seaweeds are a rich source of natural antioxidants with potent antioxidant properties. While the one-factor method has limitations in optimizing the phenolic extract, the use of developed mathematical models such as Response Surface Methodology (RSM) is recommended for more effective optimization processes. Objectives: Given the highly bioactive nature of phenolics and their numerous therapeutic applications, the primary objective of this investigation is to optimize their recovery using Response Surface Methodology (RSM). Methods: Prior to RSM, the single-factor method was applied to reveal the main factors influencing the extraction (solvent type and concentration, sample˗to˗solvent ratio, temperature, and time of extraction). The contents of total polyphenols (TP) and flavonoids were determined. While the ferric reducing power (FRP) and the free radical scavenging activity (DPPH) were used to evaluate the antioxidant activity of the extracts. Results and discussion: The results of the preliminary optimization step through sequential methodology revealed that solvent concentration, extraction duration, and temperature were the main influencing factors. All these tested extraction parameters significantly influenced total phenolic contents (TPC) and DPPH-free radical scavenging activity (FRSA) and ferric reducing power (FRP). RSM analysis using Box˗Behnken design showed that the optimal extraction conditions of total phenolic contents of algae were 23.07% acetone, 51.82 °C, and 118.02 min with values of 29.44 mg GAE/g for total phenolic extracts, 59.48% and FRSA, and 123.45 mg AAE/100g for FRP. The results obtained show that the extraction conditions have a significant effect (p<0.05) on the content of total polyphenols, flavonoids, and the antioxidant activity of the extracts. Conclusion: The developed mathematical models have demonstrated a high level of significance through sequential and RSM optimization processes for phenolic antioxidants of Ficus carica leaves. This method allows us to observe the effects of different extraction conditions on the phenolic antioxidants