Day 1 :
Karlsruhe Institute of Technology (KIT), Germany
Time : 10:00-10:45
Rolf Seifert received his Dipl.-Math from the University Freiburg, Germany in 1985. Since 1986 he works as a scientist at the Karlsruhe Institute of Technology (formerly Nuclear Research Center Karlsruhe and Research Center Karlsruhe). Under the German Support Program, he was involved in the designing of a statistical evaluation tool called PROSA which is used for NRTA in the Agency. He is now working in the field of sensor technology, especially on mathematical classification and evaluation procedures for sensor signals from multi-gas sensor systems. He is member of the technical committee “Multi Gas Sensors” of the association of German engineers (VDI) and Lecturer in Mathematics, Logic and Algebra at the Technical University Karlsruhe and at the Baden-Württemberg Cooperative State University Karlsruhe.
There is a broad field of economic online and in-situ field analysis applications like the online monitoring of volatile components for quality monitoring in food processing. Looking to beer production, for example, the quality of the raw materials like grain, hops and yeast have to be investigated because these items could be the source of a contamination with 2,4,6-Trichloranisol (TCA). TCA is a chloric aromatic hydrocarbon with intensive mildewed and moldy smell and, therefore, leads to immense damage of the product not only limited to beer production. Another field of application is the monitoring of food transport and store chains to guarantee the quality of food and to avoid harm for the consumers. Typically, Volatile Organic Compounds (VOCs) are often evaporated, which can be measured by sophisticated gas sensor systems and therefore used for investigations of the mentioned problems. The purpose of this paper is to introduce a sophisticated sensor system which was developed to measure VOCs. The principal sensing element is a four-fold sensor array on a 4x4 mm2 alumina chip (Figure 1), which comprises four micro-dispensed thick-film sensing layers of different SnO2/additive-composites. Operating MOG sensors thermo-cyclically and simultaneous sampling of the conductance yields gas specific Conductance-over-Time-Profile (CTP) features. Further-more, an innovative calibration and evaluation procedure ProSens will be introduced, which enables substance identification and concentration determination even in the case of varying environmental conditions from the characteristic CTP shapes. Many field analysis problems like those mentioned above are looking for innovative solutions. The above described sensor chip in combination with the numerical procedure ProSens is a powerful tool to solve existing problems in the area of food monitoring and food processing.
Director General Agricultural Research system, Pakistan
Keynote: Food and Beverages are the major industries for the improvement of health, daily use of life, reduction in financial crises, poverty and hunger in the world
Time : 10:45-11:30
Muhammad Usman, Director General Agricultural Research System, Government of Pakistan who retired from service after a spotless career of about 35 years with senior level experience on research and development of integrated agricultural production, industries, food and beverage, bioenergy on a sustainable way. He is basically an Agricultural Scientist with specialization of agricultural, food and biochemistry working on the yield and quality of various products and published several research papers. He is considered as the senior most scientists in the world, always participated in the international conferences as a keynote speech, renowned speaker, organizing committee member as well as moderator of the conferences around the world. He established Prominent Agro Based Industries, Agro Based Industries and Consultancy SDN BHD in Malaysia and Foundation for Rural Development in Pakistan with primary aim to work on integrated agricultural project for rural development through improvement in agriculture and consultancy services to the farmers at Malaysia.
The aim of presentation consist of food, beverages, health, daily use of life, poverty and hunger were studied and reported that food and beverages are the major industries for the improvement of health, daily use of life, reduction in financial crises, poverty and hunger in the world. Food is any substance consumed to provide nutritional support for the body. Food is usually obtained from plants and animals which contained essential food nutrients such as carbohydrate, protein, lipids, vitamins, minerals etc. The most common food groups are dairy products industries including milk, butter, ghee, yogurt, cheese, cream, ice-cream etc. Edible seed industries including corn, wheat, rice, beans, peas, lentils, nuts, sunflower, flaxseed, rapeseed, canola, sesame etc. Fruit industries include apples, orange, banana, berries, lemon etc. Vegetable industries including spinach, carrots, onion, peppers, broccoli confections, also called sugary foods including candy, soft drinks and chocolate. Meat industries include chicken, fish, turkey, beef etc. Beverage is defined as any liquid for drinking specially in other words, any type of drink except water is any liquid suitable for drinking. A beverage is a drink specially prepared for human consumption. Beverages almost always largely consist of water. The different industries of beverage including alcoholic such as wine, brandy, bear, whisky etc and non-alcoholic industries including fruits juices, fruits drinks, fruit nectars, coffee, tea, soda, coca cola, tonic water etc. In the light of above study, it is proposed to commercialized the different industries of food and beverages for absorbing millions of technical and non-technical peoples, create employment, generate income, stronger economy, reduce the crises, poverty and hunger in the world.
- Food Quality Control and Quality Assurance | Beverage Technology | Sea Food Processing | Food Preservation and Processing | Food Science and Biotechnology | Food Nutrition and Agricultural Science
Buenos Aires University, Argentina
Chulalongkorn University, Bangkok, Thailand
Time : 12:00-12:30
Kitipong Assatarakul is an Assistant Professor in the Department of Food Technology, Faculty of Science, Chulalongkorn University. He received his B.Sc. and M.Sc. in Food Technology from Chulalongkorn University, Thailand and earned his Ph.D. in Food Science and Technology at Cornell University, USA. He joined Chulalongkorn University as faculty member since 2012. His research focuses on beverage technology including thermal and non-thermal processing. He has researched on novel technologies such as UV radiation to control foodborne pathogen and spoilage microorganisms, thereby increasing the consumer’s safety. In addition, he is also working on the development of healthy beverage using herbal extract from regional plant. These will improve the quality and safety of beverage products for health-conscious consumers.
The purposes of this research were to study the effect of ultraviolet or UV radiation (0.00, 2.34, 4.68, 9.36, 18.72, 37.44 and 74.88 J/cm2) on kinetic modeling of microbiological properties (total plate count and yeast and mold count) and antioxidant properties (total phenolics, total flavonoids and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity assay or DPPH and Ferric Reducing Antioxidant Power Assay or FRAP and study the sensory properties and shelf life of UV-treated (18.72 and 37.44 J/cm2) samples compared to untreated sample (control) and pasteurized (85oC, 15 seconds) sample during storage at 4oC. Results showed that the reduction in antioxidant and microbiological properties of lychee juice subjected to UV radiation followed first order kinetic model. Coefficient of determination (R2) and rate constant (k) of first-order kinetic model of microbiological properties ranged from 0.9759-0.9935 and 0.1042-0.1060, respectively while R2 and k values of antioxidant properties ranged from 0.9781-0.9876 and 0.0008-0.0237, respectively. UV radiation significantly (p<0.05) affected on total phenolics and DPPH while total flavonoids and FRAP were not significantly affected by UV radiation. According to total plate count and yeast and mold count, control and UV-treated samples had approximately 7 and 14 days of shelf life at 4oC, respectively. UV treatment could extend shelf life of lychee juice approximately 7 days compared to control sample during storage at 4°C. When considering sensory properties of lychee juice, it was found that there were significant differences of color and flavor scores between treatments. However, UV did not significantly affect the taste score and overall liking score. Therefore, UV radiation could be an emerging technology to prevent microbial spoilage, preserve quality and enhance the shelf life of lychee juice during cold storage.
Nativbio LTD, Russia
Time : 12:30-13:00
Nativbio LTD, Russia
Sea fish roe is a unique biological material. It contains fish oil with a high content of EPA and DHA, proteins, amino acid composition of which is close to the ideal protein, vitamins A, E, D. Salted fish roe is a delicacy in many countries but for majority of people it is uneatable food. A technological solution has been discovered to use sea fish roe in a functional food. Eggs are separated from connective tissue, washed and dried. This substance can be used as a standalone product or to be an ingredient in other functional products. In a different product the roe is hydrolyzed by various proteolytic enzymes. The hydrolysate is filtered through material with different pore sizes, concentrated and dried. The dry product consists of peptides in the range of 15-5 kDa, free amino acids 10-30% and other roe components that are associated with the peptide fraction. The final composition of the product is variable, depending on the source of raw materials, a set of enzymes and conditions of enzymatic hydrolysis. One version of the product is used in production of chocolate with a content of fish roe components in the range of 10-20%.
Department of Agriculture, Bangkok, Thailand
Title: Carotenoid content, total phenolic content, antioxidant activity and carotenoids compounds of non-aqueous extracts from chillis (Capsicum annuum L.)
Time : 14:00-14:30
Akanit Pisalwadcharin has completed her Masters degree from Kasetsart University. She is an Scientist at Department of Agriculture, Thailand.
Chillis are good sources of antioxidants and phytochemicals compounds such as phenolic acids and carotenoids. The aim of this study was to determine total carotenoids contents, total phenolic contents, antioxidant activity and carotenoids compounds of two chili extracts which were Capsicum annuum L. var acuminatum Fingerh (Prik Chee Fah) and Capsicum annuum L. var. longum (Prik wan) using three different edible oils (corn, coconut and rice bran) as non-aqueous extraction media. The results showed that two chili non-aqueous extracts using rice bran oil showed a significantly higher in total carotenoids contents, total phenolic contents and antioxidant activity than the chili extracted by corn and coconut oils. Moreover, non-aqueous extracts using rice bran oil of Prik Chee Fah showed the highest total carotenoid contents (229.42 mg/ml), total phenolic contents (2,150.20 mg/ml) and antioxidant activity (97.62 μmoles Trolox/ml) compared to the other extractions. The carotenoids compounds in non-aqueous extract using rice bran oil of Prik Chee Fah consisted of capsanthin (29.15 mg/ml), zeaxanthin (4.10 mg/ml), β-cryptoxanthin (3.55 mg/ml) and β-carotene (17.20 mg/ml).
National Animal Science Research Institute (NASRI), Nepal
Time : 14:30-15:00
Netra P Osti expertise in animal nutrition, established animal nutrition laboratory in Nepal and published many papers in journals and proceedings. He holds M.Sc. Animal Science degree from Tribhuvan University Nepal, and Laboratory Quality System, short training, from Texas A&M University USA. He was senior scientist in National Animal Science Research Institute (NASRI) Khumaltar Nepal in the field of animal nutrition and feeding, previously livestock development officer in Department of Livestock Services (DLS) Nepal now freelancer.
Nepal is an agriculture-based country and livestock is an integral part of the Nepalese economy, contributing about 26 percent to the Agricultural Domestic Products (AGDP). Livestock provide meat, milk, eggs for human nutrition; wool and hides for the industry and manure for crop production. Nepal has a large livestock population consisting of cattle 7 million, buffaloes 5 million, goats 10 million, sheep 1 million, pigs 1 million and fowl 48 million. The buffalo population ranks 4th among buffalo rearing countries but their production is very low as compared with those in neighbouring countries such as India and Pakistan. The overall low production of livestock is mainly due to low supply of quality animal feeds and inefficient use of available feed resources. In order to rationally use the available feeds, their assessments and use were studied in three ecological belts and five development regions in Nepal. This study is based on review of various journals, conference proceedings, project reports, statistical data from the statistics department, expert opinion and analysis by the team members.
Livestock herd composition and sizes vary in the three ecological zones (mountains, hills and Terai). Majority of the livestock holdings are small (5-7 animals per household) in size. Among the ruminant animals, the buffalo population has increased from 4 to 5 million in the last ten years. Buffalo contribute approximately 72 percent of milk and 65 percent of domestic meat supply. Lime, Parkote and Gaddi buffaloes are native breeds, while Murrah and their crosses are the improved breed of buffalo in Nepal. The cattle population has remained stable (7 million) for the last decade and its contribution is 28 percent to the national milk supply. Shree, Pahadi, Khaila and Terai cattle are native while Jersey and Holstein are exotic breeds of cattle in Nepal. The sheep population has decreased from 0.82 to 0.81 million in the last ten years, while goat numbers are steadily increasing (from 7 to 10 million in the last decade). Among the non-ruminant livestock species chicken numbers increased considerably from 23 to 48 million in the last decade to supply eggs and meat to fast growing urban human population.
Extensive and semi-extensive livestock production systems exist in the mountain zone, and in the high-altitude alpine regions transhumance grazing system is practiced where livestock are grazed on local pasture in foothills and forest during winter (November to March) and spend late spring and summer months (April to October) on high altitude pastures. In the hills, extensive and semi-intensive production systems are common while small numbers of animals are raised in intensive system. Tree fodder, grasses and legumes collected from forest and cultivated lands and rice straw are the major feeding resources in semi-intensive and extensive system in the hills of Nepal. Locally made semisolid (Kundo) from kitchen waste, and maize flour mixed with rice bran is given to productive animals during evenings. Livestock rearing in Terai resembles to that in hilly region with respect to extensive and semi-extensive production systems. Near to urban and semi-urban areas commercial livestock production exists to cater for the demand of urban populations.
Crop residues, rice and wheat straw, maize stovers, tree fodder, leaf litters and other green fodder collected from cultivated lands and forest are the major feeding resources in Nepal. In concentrate, maize is the main feed ingredient followed by rice bran, wheat bran, soybean meals, mustard cake, sunflower cake and other legumes by-products. Due to fast growing poultry and dairy farming, the local production of maize and soybean does not meet national feed demand, and these are imported from India and other countries.
The native feed supply in Nepal is not adequate to meet the demand of existing livestock and poultry. There is a deficit of 33 percent in dry matter, 38 percent in crude protein and 42 percent in metabolizable energy. The human edible protein output per unit of human edible protein consumed by livestock is higher in ruminants, especially in sheep and goats, than in pigs and poultry. This demonstrates greater scope of ruminant livestock contribution to food security in Nepal with scarce feed resources.
Buenos Aires University, Argentina
Title: Development of a tangerine-orange juice added with yerba mate (Ilex paraguariensis) extract and processed by UV-C light
Time : 15:00-15:30
Sandra Guerrero works as a Researcher and Professor at the Natural and Exact Science School, University of Buenos Aires and at the National Council of Scientific and Technical Research(CONICET) as Principal Researcher in Buenos Aires, Argentina. In 2014, she received the Certified Food Scientist credential given by the International Food Science Certification Commission, USA. She is a coauthor of one book edited by FAO and translated to four languages devoted to the implementation in rural areas of hurdle strategies for tropical fruit preservation. During the last 25 years, her research activity has been focused on the use of emerging technologies for food preservation. She has published numerous papers in high impact peer-reviewed journals, 19 chapters in books, and 180 presentations in scientific events. Her latest projects had to deal with the use of the non-thermal technologies under a hurdle approach to enhance food safety as well as organoleptic and nutritional quality.
UV-C light (254 nm) assisted by other stress factors may be a good alternative to traditional thermal treatment for reducing microbial contamination in turbid juices, thus overcoming the UV-C processing limitations imposed by suspended matter which can harbor microbial cells. Yerba Mate (YM) has been largely studied due to antioxidant and antimicrobial properties, among others, attributed to its Phenolic Compounds (PC). The aim of this study was to develop a tangerine-orange juice (1:1, pH:3.9±0.1, 11.6±1.0 °Brix, 1309±20 NTU, absorption coefficient:0.41 %v/v, D3,2: 24.0±1.4 µm, D4,3: 330.0±27.7 µm) processed by UV-C (0.87 m-long annular reactor, 2 serially connected UV-C lamps; 30 watts, 1.8 L/min; 15min; 13.1 kJ/m2; 20°C) added with Yerba Mate Extract (YME). For the YME, leaves were sonicated (20 kHz; 95.2 µm; ethanol; 25°C), freeze-dried and subsequently added to the juice (0.4 %w/v). UVC/H+YME treated samples were periodically examined for native flora. PC by Folin-Ciocalteau reaction, Flavonoid Content (FC), Total Antioxidant Activity (TAA) by DPPH and ABTS, color (CIELab values), turbidity, °Brix and pH were also assessed before and after treatment. Unprocessed juice with or without YME (controls) exceeded the recommended limit for total coliforms since day 0 of storage. UV-C treatments was highly effective as it reduced native flora by 4.0- 5.1 logs whitout being able to recover during 15 days of storage. FC, PC TAADPPH, TAAABTS were increased up to 4.0, 2.0, 1.5 and 2.1 times after YME addition of processed juice, respectively, compared to control juice (FC= 0.15±0.06 mg Catequin Eq/mL, TAADPPH= 3.69±0.14 mg Trolox Eq/mL, TAAABTS=0.58±0.40 mg Trolox Eq/mL, PC=0.63±0.10 mg GAE/mL). UV-C+YME treated juice showed higher turbidity, °Brix and lower a* values, indicating that samples were less red, but greener than control; whereas, pH was not altered by the treatment. Consumer profiling studies revealed that the UVC/H+YME treated juice was well accepted by a group of consumers interested in sour products with herbal taste and strong aroma. This study expands the use of UV-C processing to turbid systems obtaining promising results as regards to the development of an innovative beverage.
The American University in Cairo, Egypt
Title: Antimicrobial activity of grape seed and skin extracts coated on corona treated LDPE and PET films
Time : 16:00-16:30
Nahla Mohamed Abdel Khalek Khalil has completed her MS in Food Chemistry at The American University in Cairo, School of Sciences and Engineering, Chemistry Department in 2017. She is currently working as Research Assistant in the Chemistry Department, The American University in Cairo. She started disscussions concerning her PhD with her advisors at The American University in Cairo, she intended to complete her research focusing on the other important aspects of both grape seed and skin extracts e.g. anticancer and antinflamatory properties.
Incorporation of natural bioactive agents in the packaging material to increase the shelf life of meat products is a promising technology. Grapes are of special interest because of their high content of phenolic compounds that have documented antimicrobial and antioxidant properties. The aim of the present work was to investigate grape seed (GSE) and skin (GSKE) extract antibacterial activity through their incorporation into bioactive LDPE/PET films that could be used as food packaging materials for poultry and meat products. Commercial corona treated LDPE and PET were coated with either grape seed or grape skin extract. The agar plate diffusion method was used for the investigation of the antimicrobial properties of both extracts’ coated films against E. coli chosen as a Gram-negative bacterium and Staphylococcus aureus as a Gram-negative one. LDPE and PET films coated with GSE showed inhibition zones of E. coli growth in the range of 16-25 mm, while S. aureus growth inhibition zones were in the range of 15-20mm. For LDPE corona films coated with GSE, the Minimum Inhibitory Concentration (MIC) was 0.1 gm for E. coli and 0.15 gm for S. aureus; while for corona treated PET films/GSE, the MIC for both E. coli and S. aureus was 0.1 g/area of regular petri dish. Corona treated LDPE and PET coated with GSKE showed an inhibition zone range of 13-16.3 mm for E. coli and 12-20 mm for S. aureus. For LDPE corona films/GSKE, the Minimum Inhibitory Concentration (MIC) was 0.05 gm for E. coli and 0.2 gm for S. aureus. For corona treated PET films/GSKE, the MIC was 0.1 gm for E. coli and 0.15 g for S. aureus. The Total Phenolic Content of both GSE and GSKE was determined to be 315.32 g (GAE)/kg, and 265.326 g (GAE)/kg for GSE and GSKE respectively using the Folin- Ciocalteu method. The coated films (LDPE/GSE or LDPE/GSKE), were used to wrap fresh ground chicken patties. TVC, Pseudomonads, Brochothrix thermosphacta, Lactic acid bacteria and Enterobacteriaceae counts were determined during a storage period of 10 days. Sampling was carried out on day 0, 2,4, 6, 8, and 10 for test samples and until day 8 for controls. There was a reduction in the population of the bacteria tested in the range of 0.2-1.4 log cfu/g in case of GSE, while with GSKE the reduction of bacterial populations range was 0.3-1.95 log cfu/g. Chicken patty microbiological shelf life for the LDPE/GSE samples, LDPE/GSKE samples and control samples was 10, 10 and 8 days respectively.
Marine and Environmental Sciences Centre, Portugal
Time : 16:30-17:00
Teresa Mouga is a Coordinating Professor (Senior Lecturer) at School of Tourism and Maritime Technology, Polytechnic Institute of Leiria Portugal. She developed research in MARE – Marine and Environmental Sciences Centre dealing with seaweed growth in laboratory condition and seaweed biotechnology: Bioactive compounds extraction, and relevant bioactivities, such as antioxidant and antimicrobial activities. She is involved in several research projects, namely the EU project AMALIA - Algae-to-Market Lab Ideas - Adding value to marine invasive seaweeds of the Iberian northwest, Financing program: Implementation of the European Maritime and Fisheries Fund. Work Programme 2016, Action 18.104.22.168 – Blue Labs: Innovative solutions for maritime challenges, 2017-2019 and the national project Seaweed Feeds: fish feed supplementation, financed by Mar2020.
Seaweeds have long been used as food in Asian countries. Migrations and globalization have brought the attention of European countries to these healthy foods, greatly increasing the consumption of seaweeds around the world, including in countries where its consumption it was not traditional. Seaweed production is also increasing dramatically, being currently of around 30 thousand tons a year. Despite the growing interest, there are but a few commercial species produced, such as Saccharina japonica (kombu), Porphyra (nori), Undaria pinnatifida (wakame), Ulva/Monostroma (Aonori), mainly for food, and Kapaphyccus alvarezi (elkhorn sea moss), Eucheuma cottonii (guso), Gracilaria (ogonori, or sea moss) and Chondrus crispus (irish moss) for phycocolloid extraction. In general, seaweeds exhibit high nutritional value due to high concentrations of proteins, vitamins and minerals. They also provide low energy content due to the low levels of lipids, of which many are w-3 and w-6 fatty acids, together with high concentration of polysaccharides of low digestibility. Besides the nutritional values for some of these compounds has shown to exhibit antioxidant, antimicrobial, antiviral, antitumor and many other interesting qualities. The genus Gracilaria, is no exception. As such, a comprehensive study of the nutritional profile and antimicrobial capacity of different populations of the red seaweed Gracilaria gracilis (Rhodophyta, Gracilariales) will be presented. Moisture, ash, protein and amino acids content, crude fibre, vitamin C, phycocolloids, fat content and the corresponding fatty acid profile were analyzed, and the results will be discussed. The results obtained are consistent to those usually reported for this genus and red seaweeds in general, indicating low levels of fatty acids, and high content in fiber, protein and essential amino acids. Interesting antimicrobial activities were also registered. Therefore, besides its common commercial uses, we can state that G. gracilis stands as a natural source of compounds with true nutritional and health value.
University of Reading, UK
Title: Studies on the effect of different cooking procedures of Brassica vegetables on the formation of isothiocyanates and their antimicrobial activities
Time : 17:00-17:30
Dr. Sameer kalil Ghawi, PhD, MSc, PgD, BSc, MIFST, Food Technologist, Food Processing Centre, Department of Food and Nutritional Sciences, University of Reading, UK.
Sulforaphane, a naturally occurring cancer chemo preventive, is the hydrolysis product of glucoraphanin, the main glucosinolate in broccoli. The hydrolysis requires myrosinase isoenzyme to be present in an active state; however, cooking leads to its denaturation. In order to ensure glucoraphanin hydrolysis, broccoli must either be mildly cooked or active sources of myrosinase can be added post-cooking.
In this study, mustard seeds as exogenous source of myrosinase were added to cooked broccoli as a condiment with a view to intensify the formation of sulforaphane.
Thermal inactivation of myrosinases from broccoli and mustard seeds was studied. Thermal degradation of broccoli glucoraphanin was also investigated. The inhibition activity of sulforaphane was assessed against a variety of Gram negative and Gram-positive bacteria using the disk diffusion method. For comparative purpose, a number of antibiotics were also tested against the same set of microorganisms. In addition, the effect of mustard seeds addition on sensory profiling and consumer acceptability was assessed.
Mustard seed myrosinase showed higher thermal stability than broccoli myrosinase. Limited thermal degradation of glucoraphanin (about 10%) was observed when broccoli was sous vide cooked. Addition of mustard seed powder to cooked broccoli reinitiated the formation of sulforaphane. The antimicrobial assays demonstrated that sulforaphane extracted from broccoli had a wide spectrum of inhibition against both Gram positive and Gram-negative bacteria. Several pathogens that were resistant to ampicillin, such Salmonella Typhimurium DT104 T10, E. coli O157:H7 VT and E. coli K-12, and to tetracycline, such as Salmonella hadar, were sensitive to sulforaphane.
Addition of mustard seed powder significantly changed sensory attributes of broccoli samples and affected consumer liking. Despite the significant increase in pungency and burning sensation in samples with added mustard seeds, a considerable number of consumers (32%) liked it. This suggests that optimised addition of Brassica condiments (e.g. mustard seeds, rocket, horseradish, watercress) to cooked broccoli may be a route to enhance bioactivity of cooked broccoli without compromising consumer acceptability.
National University of Lujan, Buenos Aires, Argentina
Title: Effect of the type of acid on the formation of soluble complexes of thermally denatured β-lactoglobulin and Carboxymethyl Cellulose
Time : 17:30-18:00
Farias Maria Edith is a Food Engineer, PhD in Industrial Chemistry. She is working as Thermodynamics and Physicochemistry Professor at University National of Lujan, Argentina and Associate Research of Commission Investigaciones Cientificas of Buenos Aires Province.
The objective of this work was to study the effect of type of acid (hydrochloric, lactic, citric and acetic) on the formation of soluble complexes of thermally denatured β-lactoglobulin (β-lg) and Carboxymethyl Cellulose (CMC). β-lg was prepared at different concentrations (0.125, 0.250 and 0.500% w/w) at pH 7.0 and heated at 80°C for 15 minutes. The complexes were formed with 0.3% (w/w) of CMC and two percentages of protein (0.125 and 0.250) at pH 4. They were characterized by UV-visible (absorbance at 600 nm), fluorescence, dynamic light scattering (DLS), flow rheology and FTIR. The complexes showed greater coefficient of consistency, K, and lower pseudoplastic index (n) than CMC pure. The 0.125 β-lg/0.3 CMC complexes formed with acetic or lactic acids had the highest K and the lowest n. The 0.250 β-lg/0.3 CMC complexes formed with acetic acid had the highest K and the lowest n. Interestingly, K decreased with the protein ratio increase for the β-lg/CMC complexes formed with HCl. The NaCl addition at 100 mM or more decreased the turbidity of all soluble complexes. However, the complexes 0.125 β-lg/0.3 CMC formed with acetic acid and the complexes 0.250 β-lg/0.3 CMC formed with acetic, lactic and citric acid showed stable curves in the fluorescence tests. The FTIR spectra of the complexes showed electrostatic interactions between the macromolecules. It is concluded that the complexes formed with acetic acid have high electrostatic interaction, even in presence of salt, for both concentrations of proteins studied. On the other hand, the complexes 0.250 β-lg/0.3 CMC formed with HCl revealed an excess of protein that lowered the viscosity of the systems. This study shows that the type of acid used in the formation of a soluble complex is as essential as the protein-polysaccharide ratio, the pH or the nature of the polymers. This knowledge will be used in the future for the replacement of fat in food systems like yogurt.