Pork Liver Freshness Evaluated through Spoilage Microbiota and a Consumer Test in Shelf Life Extension Experiment

Luís A. S. C. Patarata,Margarida I. F. C. Rouxinol,Rita O. Silva

doi:10.1155/2020/1092865

Luís A. S. C. Patarata, Margarida I. F. C. Rouxinol

Open Access

https://doi.org/10.1155/2020/1092865

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Abstract

Pork liver is an affordable product, very much appreciated by some consumers. Packaged pork liver has a short shelf life that can represent an additional cost to the producers. This work aimed to assess the relationship between consumer acceptability, evaluated through both a test made live with photography and samples to be smelled and an internet survey platform based only on photography, and the counts of the main spoilage microorganisms, on pork liver samples stored from the actual end of shelf life (ESL) and two extra days of storage times, ESL + 2 and ESL + 4. The results indicate limited usefulness of microbial counts, once they were generally very similar between accepted and nonaccepted samples, with total viable count below 7 Log CFU/g. Both methodological approaches revealed that there is no margin to extend the shelf life from the three days previously established by the manufacturer. It was observed that pork liver packaged with modified atmosphere had similar evaluations of freshness using internet-based or live test with consumers, with a drop in purchase intention from 87.5% at ESL to 13.2% at ESL + 2, when the assessment was made through the internet-based test. When the test was made live, the purchase intention had the same trend, but the drop was smaller, from 61.5 at ESL to 21.2% at ESL + 2. The purchasing intention was lower when the consumers had the opportunity to smell the samples but considering the decision of defining the end of shelf life based on 50% of consumers accepting, it was similar in almost all the cases.

Highlights

Pork liver is a budget product, rich in protein, minerals like iron, zinc, and manganese, and many essential nutrients such as amino acids and fatty acids with an interesting ratio PUFA/SFA [1, 2]
A similar trend was observed for specific spoilage microorganisms putatively associated with liver spoilage
Using a consumer test to define the proportion of purchasing intentions of the liver aged after the end of shelf life (ESL), it was observed that it is not possible, once two extra storage days results in a drop in the freshness evaluation and correspondent purchasing intention to values below the generally accepted of 50%. e perception of freshness of raw liver depends on its aspect, namely, the bright red colour, absence of discoloration spots, and absence of visible slime and the odour that can be modified due to the activity of spoilage microorganisms, autolytic mechanisms, or the interaction between both [3]. e mechanisms underlying the spoiled odor of the liver are complex

Summary

Introduction

Pork liver is a budget product, rich in protein, minerals like iron, zinc, and manganese, and many essential nutrients such as amino acids and fatty acids with an interesting ratio PUFA/SFA [1, 2]. It is a product very appreciated by a niche of consumers accustomed to traditional cuisine. As with meat and other offals, the liver has a limited shelf life that might have difficulty in its commercialization [3]. Considering offal composition, pH, and moisture content, Journal of Food Quality there is no obvious reason to have a higher spoilage rate in offal than in meat, for similar storage conditions [3, 9]

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Results

Conclusion