Metodologia dos limiares hedônicos variando mais de um estímulo: aplicação na redução de cloreto de sódio em biscoito salgado

Abstract

The hedonic threshold methodology (HTM), by calculating the compromised acceptance threshold (CAT) and the hedonic rejection threshold (HRT), allows to identify the beginning of the reduction of acceptance and sensory rejection of foods, varying the intensity of one or more stimuli. One of the applications of HTM is to determine the maximum reduction of sodium chloride without affecting acceptance (CAT) and result in sensory rejection (HRT) of foods. The objective was to apply HTM to determine hedonic thresholds (CAT e HRT) for concentration of sodium chloride (NaCl) in salty cracker, varying the intensity of more than one stimulus simultaneously. In all, four experiments were carried out, in all of them the control cracker contained 1,81% NaCl and the NaCl concentration was reduced from that concentration. The first experiment, varying only one stimulus, the CAT and HRT were determined for the NaCl concentration of the cracker, through five acceptance test sessions. In the second experiment, through of Central Composite Rotatable Design (CCRD) and HTM, varying two simultaneous stimuli (reduction of NaCl and addition of KCl), CAT and HRT were determined, with 11 acceptance teste sessions. In the third and fourth experiments, the Mixture Design and HTM were used, varying three simultaneous stimuli: NaCl, KCl and yeast extract and enzymatic preparation, respectively, for determination of CAT and HRT. Ten sessions of acceptance teste were carried out in both experiments. In the first experiment, it was found that, from the reduction of 59.67% in the NaCl content (1.81% to 0.73%) there is a reduction in sensory acceptance and, only from the 92.81% reduction in NaCl content (1.81% for 0.13%), sensory rejection of the cracker occurs. In the second experiment, it was observed that, by adding 0.896% KCl, it was possible to achieve a 78.06% reduction in NaCl content, to begin to reduce sensory acceptance (1.81% to 0.397%). In addition, it was found that by adding KCl, it is possible to reduce the NaCl content 100% without sensory rejection of the cracker. In the third experiment, it was found that, when adding 1.149% KCl, there was a reduction in the sensory acceptance of the cracker by reducing the NaCl content by 64.03% (1.81% to 0.651%); and at the adding 1.783% KCl and 0.017% yeast extract or 0.693% KCl and 1.107% yeast extract it is possible to reduce the NaCl content (100%) as much as possible without resulting in sensory rejection of the cracker. In the fourth experiment, it was found that by adding 0.358% KCl and 0.356% of enzymatic preparation, from the 40% reduction in NaCl concentration (from 1.81% to 1.086%) compromises the sensorial acceptance of the cracker. When adding 1.215% KCl and 0.573% of enzymatic preparation, sensorial rejection of the cracker begins to occur when it reduces the NaCL content by 99.34% (1.81% to 0.012%). Therefore, by applying the HTM with the variation of two and three stimuli, it was possible to reduce the sodium chloride content of the crackers, and the addition of only KCl provided a greater reduction in NaCl, compared to the other components used. In addition, through the Mixture Design together with MLH, it was possible to determine, for the first time, sensory thresholds by varying the intensity of three stimuli simultaneously, which expands the applications of hedonic thresholds by the food industries.