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II-24. Sensory evaluation of mayonnaise with fish oil
342
Abstracts of Poster Presentations
11-24. SENSORY EVALUATION OF MAYONNAISE WITH FISH OIL Charlotte Jacobsen and Else Green, Department of Biotechnology, Building 22 1, Technical University of Denmark, 2800 Lyngby, Denmark
It is well documented that omega-3 fatty acids have a number of beneficial effects on the human organism. One way of increasing the population’s intake of omega3 fatty acids is by enriching foods with fish oil. In this experiment, fish oil was incorporated into mayonnaise, at a level of 20% of the fat phase. An antioxidant mixture comprising of ascorbic acid, lecithin and tocopherol was used to protect the mayonnaise against oxidation. This antioxidant mixture had proved very efficient in bulk fish oil. Different concentrations of the antioxidant mixture were used. Mayonnaise without fish oil and antioxidant was used as a reference. The shelf life of the produce, as well as the effect of the antioxidant, was assessed by sensory evaluation and chemical analyses and by an accelerated test method. With regard to the sensory evaluation, a scale from one to ten was used for the overall impression of smell and taste. In addition to this, the flavor profile method was used to describe the taste and smell of the samples. The results of the sensory evaluation indicated a shelf life of mayonnaise with 20% fish oil, but without antioxidant, of more than ten weeks. However, it was very surprising that the addition of the antioxidant system caused a shorter shelf life. The higher the antioxidant concentration, the shorter the shelf life. The profiles showed that the addition of the antioxidant system gave rise to a fishy and rancid flavor of the product right from the commencement of the experiment. The intensity of the fishy and rancid taste increased with increasing antioxidant concentration. We did not find a similar negative effect of the antioxidant system when evaluating the shelf life by chemical and accelerated analyses. These results comply with recent findings reported in the literature (Frankel), that there is a fundamental difference between pure oil and food emulsions with respect to the effect of antioxidants.
11-25. OPTIMIZED TEA BLENDS THROUGH MIXTURE DESIGN AND PATTERN MATCHING Chand Nagin, M. R. Asha, G. K. Sarvamangala, Rajalakshmi and Shanti Narasimhan,
D.
Department of Sensory Analysis and Statistical Services, Central Food Technological Research Institute, Mysore013, India
Tea is recognized for its delicate balance of taste and aroma. Tea blending and cup tasting is a specialized art,
carried out by cup tasters. This paper details a different approach as in use situation with systematic efforts at profiling the perceived notes in tea. Mixture design was adapted to blend five tea cultivars (from the upper ranges of Nilgiris) requiring 36 experiments for optimization. The samples were profiled over a number of sessions and data subjected to canonical discriminant analysis which revealed large variation in the quality profile of the blended samples, and therefore, the basic objective of planning/designing the blends was achieved. The intensity data on the nine attributes, including the overall quality was modelled through compatible polynomials typical of mixture designs used. Two optimized blends were required, one the premium and the other general purpose. The premium blend was to be rich in tea aroma and body but low in acrid, astringent and bitter notes and the general blend, a compromise of aroma, body, acrid, and astringent notes. The optimized levels for each type were worked out with flexible polyhedron search method of Nelder and Mead which were subsequently verified. The blending behavior of the tea cultivars has been discussed through contour plots for different attributes perceived. The empirical confirmation of the quality of predicted two blends and the market sample has been reported over the nine important attributes. The premium blend is high in overall quality (OQ of 9.4 and tea aroma (8.3), lowest in bitterness (2.4) and astringency (2.2); the general blend was lower in OQ (8.4), was dominant in color (8.2), tea aroma (7.8), but little high in body (8.0) and bitterness (2.6). The market sample was lowest in OQ (7.2), with high color (9.0), high bitterness (5.6), and astringency (5.2).
11-26. SENSORY QUALITY
OF TOMATOES
Asa Haglund, Lisbeth Johansson and Josef Dlouhy, Department of Domestic Sciences, University of Uppsala, Dag Hammarskjolds vag 21, S-752 37 Uppsala, Sweden
Quality of foods includes the appearance and the chemical composition of the product as well as the taste and the consumers attitudes toward the farming system or animal-rearing techniques. The aim of this study was to investigate how different fertilizers affect the sensory quality of greenhouse-tomatoes in ecological gardening. Earlier studies has showed that there is no difference in taste between conventional and organic grown tomatoes (Basker 1993). In another study between conventional grown tomatoes with different nitrogen (N) and potassium (K) fertilization, a panel of 16 members preferred for flavor the tomatoes receiving the lower level of N-K fertilization (Wright 1985). The strain ‘Elin’ was used in the study. The experiment included five trials with varying manure and mulch. Trial A, B, C, and D were cultured with composted farmyard manure, straw, soil
Abstracts of Poster Presentations
11-24. SENSORY EVALUATION OF MAYONNAISE WITH FISH OIL Charlotte Jacobsen and Else Green, Department of Biotechnology, Building 22 1, Technical University of Denmark, 2800 Lyngby, Denmark
It is well documented that omega-3 fatty acids have a number of beneficial effects on the human organism. One way of increasing the population’s intake of omega3 fatty acids is by enriching foods with fish oil. In this experiment, fish oil was incorporated into mayonnaise, at a level of 20% of the fat phase. An antioxidant mixture comprising of ascorbic acid, lecithin and tocopherol was used to protect the mayonnaise against oxidation. This antioxidant mixture had proved very efficient in bulk fish oil. Different concentrations of the antioxidant mixture were used. Mayonnaise without fish oil and antioxidant was used as a reference. The shelf life of the produce, as well as the effect of the antioxidant, was assessed by sensory evaluation and chemical analyses and by an accelerated test method. With regard to the sensory evaluation, a scale from one to ten was used for the overall impression of smell and taste. In addition to this, the flavor profile method was used to describe the taste and smell of the samples. The results of the sensory evaluation indicated a shelf life of mayonnaise with 20% fish oil, but without antioxidant, of more than ten weeks. However, it was very surprising that the addition of the antioxidant system caused a shorter shelf life. The higher the antioxidant concentration, the shorter the shelf life. The profiles showed that the addition of the antioxidant system gave rise to a fishy and rancid flavor of the product right from the commencement of the experiment. The intensity of the fishy and rancid taste increased with increasing antioxidant concentration. We did not find a similar negative effect of the antioxidant system when evaluating the shelf life by chemical and accelerated analyses. These results comply with recent findings reported in the literature (Frankel), that there is a fundamental difference between pure oil and food emulsions with respect to the effect of antioxidants.
11-25. OPTIMIZED TEA BLENDS THROUGH MIXTURE DESIGN AND PATTERN MATCHING Chand Nagin, M. R. Asha, G. K. Sarvamangala, Rajalakshmi and Shanti Narasimhan,
D.
Department of Sensory Analysis and Statistical Services, Central Food Technological Research Institute, Mysore013, India
Tea is recognized for its delicate balance of taste and aroma. Tea blending and cup tasting is a specialized art,
carried out by cup tasters. This paper details a different approach as in use situation with systematic efforts at profiling the perceived notes in tea. Mixture design was adapted to blend five tea cultivars (from the upper ranges of Nilgiris) requiring 36 experiments for optimization. The samples were profiled over a number of sessions and data subjected to canonical discriminant analysis which revealed large variation in the quality profile of the blended samples, and therefore, the basic objective of planning/designing the blends was achieved. The intensity data on the nine attributes, including the overall quality was modelled through compatible polynomials typical of mixture designs used. Two optimized blends were required, one the premium and the other general purpose. The premium blend was to be rich in tea aroma and body but low in acrid, astringent and bitter notes and the general blend, a compromise of aroma, body, acrid, and astringent notes. The optimized levels for each type were worked out with flexible polyhedron search method of Nelder and Mead which were subsequently verified. The blending behavior of the tea cultivars has been discussed through contour plots for different attributes perceived. The empirical confirmation of the quality of predicted two blends and the market sample has been reported over the nine important attributes. The premium blend is high in overall quality (OQ of 9.4 and tea aroma (8.3), lowest in bitterness (2.4) and astringency (2.2); the general blend was lower in OQ (8.4), was dominant in color (8.2), tea aroma (7.8), but little high in body (8.0) and bitterness (2.6). The market sample was lowest in OQ (7.2), with high color (9.0), high bitterness (5.6), and astringency (5.2).
11-26. SENSORY QUALITY
OF TOMATOES
Asa Haglund, Lisbeth Johansson and Josef Dlouhy, Department of Domestic Sciences, University of Uppsala, Dag Hammarskjolds vag 21, S-752 37 Uppsala, Sweden
Quality of foods includes the appearance and the chemical composition of the product as well as the taste and the consumers attitudes toward the farming system or animal-rearing techniques. The aim of this study was to investigate how different fertilizers affect the sensory quality of greenhouse-tomatoes in ecological gardening. Earlier studies has showed that there is no difference in taste between conventional and organic grown tomatoes (Basker 1993). In another study between conventional grown tomatoes with different nitrogen (N) and potassium (K) fertilization, a panel of 16 members preferred for flavor the tomatoes receiving the lower level of N-K fertilization (Wright 1985). The strain ‘Elin’ was used in the study. The experiment included five trials with varying manure and mulch. Trial A, B, C, and D were cultured with composted farmyard manure, straw, soil