Orientador: Prof. Dr. Ivanor Nunes do Prado

 Data da Defesa: 15/02/2016



INTRODUCTION In recent years, consumer demand for safer food and quality of meat, as well as meat products with reduced levels of fat, sodium chloride, cholesterol and nitrite increased. Processed meat products have significant contribution in levels of sodium consumed by the population, however, the use of substitutes, such as potassium chloride is limited, mainly due to its bitter taste. The partial replacement of sodium chloride by potassium chloride with the addition of herbs and spices to beef burger, it is a promising solution for decreasing sodium and maintenance palatability of meat products. The maintenance of the beef burger shelf life with sodium reduction still depends on other technological variables such as keep acceptable levels of lipid oxidation and microbial counts. The use of active packaging is currently of the most dynamic technologies used to preserve meat quality. Through the release of active agents, such as essential oils of oregano, contributing to the preservation of shelf life of low-sodium meat products, without changing its technological and sensory characteristics, eliminating the use of synthetic additives. AIMS The aim of the study was developed hamburgers with reduced sodium content by 25% (F25) and 50% (F50) and analyzed regarding their physical, chemical, microbiological, sensorial characteristics and market research. Description of the sensory profile of low-sodium burgers using the methodology of Quantitative Descriptive Analysis (QDA). The second aim was evaluate the efficacy of active packaging (with addition of essential oils), while preserving quality of beef burger with 25% and 50% of reduction of sodium chloride, stored for 120 days under freezing. MATERIAL AND METHODS Hamburgers were prepared in order to replace the effects of sodium chloride (NaCl) by potassium chloride (KCl), also aromatic herbs and species were added( Allium sativum, Oreganum Vulgare, Bixa orellana, Capsicum frutescens). Chemical analysis were performed in triplicate, following methodology proposed by AOAC. Sensorial tests were performed on both type of consumers (healthy and hypertensive) using an hedonic scale, principal component analysis and Quantitative Descriptive Analysis (QDA) with 12 selected and trained tasters using as criteria the discriminative power, reproducibility and individual consensus among themselves. In addition, a market research with 250 consumers was done. Four treatments were evaluated in order to know efficiency of biodegradable and active packaging (produced by extrusion) applied to beef burgers with low sodium content stored at -18 ° C for 120 days through various techniques. Treatments studied were: Beef burgers with 25% (B25) and 50% (B50) of sodium reduction in biodegradable packaging and beef burger with 25% (BOEO25) and 50% (BOEO50) of sodium reduction biodegradable packaging with 1% oregano oil. It was analyzed lipid oxidation (TBARS), microbiological, pH at 1, 30, 60, 90 and 120 days of 13 storage, chemical composition analysis (moisture, ash, protein, lipid) at time 1 and 120 days, activity analysis water (Aw), cooking loss, texture, and color (L , a *, b *) at 1, 60 and 120 days and sensory analysis at 30 and 120 days. RESULTS AND DISCUSSION On article 1 it was observed that the highest rates on texture were reported for hamburgers belowing to 50% sodium reduction treatment. Although microbiological aspects were adequate and acceptability of low-sodium hamburgers remained over 70%. Hypertensive consumers had great overall acceptability (92%) and only slightly detected sodium decrease. The Quantitative Descriptive Analysis (QDA) of the article 2 topic has showed that low-sodium burgers had lower taste of fat and salt when compared to the control and taste and odor of added spice, this difference shows that the reduction of sodium in the burger causes increased intensity perceived by the panelists compared the presence of spices in the product. On article 3, market research results revealed great consumers´ interest in acquiring products with reduced quantities of sodium. The composition of packaging during the time of storage on low-sodium beef burgers did not influence attributes as: moisture, crude protein, total fat, ash, cooking loss and water activity. Active packaging which contained also oregano oil showed higher color protection on burgers during the storage period. Texture showed stable on all days of storage, being stabilizate on the other periods until the end of storage (120 days) burgers from 25% sodium reduction and packaged with 1% oregano essential oil (BOEO25) had better taste and aroma, getting a acceptability index above 80% for both periods (30 and 120 days). The incorporation of 1% of oregano essential oil into the packaging reduced lipid oxidation of burgers analyzed untills 14% when it is compared with packaging without oregano adition. Microbiological analyzes were maintained adequate and stable during the complete storage time. The use of active packaging with essential oil of oregano for the storage of low-sodium burgers was proved to be viable alternative, allowing production and commercialization, maintaining their quality and contributing to its acceptability by consumers. CONCLUSION The microbiological, chemical and physical characteristics of low-sodium beef hamburgers were kept. From the sensorial point of view, the replacement of up to 25% is adequate for both types of consumers and 50% of sodium by potassium in beef hamburgers were better accepted for hypertensive than healthy consumers. The addition of spices (Allium sativum, Oreganum Vulgare, Bixa orellana, Capsicum frutescens) to the product attributes improved flavor, aroma and texture of low-sodium burgers, masking the taste of fat. The reduction of sodium in 25% and 50% did not affect the quality of the burgers during the storage time, as well as, their physical and microbiological characteristics. Active packaging with 1% of oregano essential oil, prove its feasibility to control lipid oxidation in beef burgers during its shelf life, improving the sensory quality. Key Words: Sodium chloride. Potassium chloride. Quality control. Beef burger. Active packaging.


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