Sensory evaluation of seafood freshness using the quality index method: A meta-analysis

Current applications and future trends of artificial senses in fish freshness determination: A review

Fish is a highly demanding food product and the determination of fish freshness is crucial as it is a fundamental factor in fish quality. Therefore, the fishery industry has been working on developing rapid fish freshness determination methods to monitor freshness levels. Artificial senses that mimic human senses are developed as convenient emerging technologies for fish freshness determination. Computer vision, electronic nose (e-nose), and electronic tongue (e-tongue) are the emerging artificial senses for fish freshness determination. This review article is uniquely worked upon to investigate the current applications of the artificial senses in fish freshness determination while describing the steps, and fundamental principles behind each artificial sense, comparing them with their advantages and limitations, and future trends related to fish freshness determination. Among the artificial senses, computer vision determines the freshness of fish in a completely nondestructive way while the e-tongue determines the freshness of fish in a completely destructive way. There are developed e-noses for fish freshness determination in both destructive and nondestructive ways. By analyzing visual cues such as color, computer vision systems can assess fish quality without the need for physical contact and it makes computer vision suitable for large-scale industrial fish quality assessing applications. Overall, this review study reveals artificial senses as a proven replacement for traditional sensory panels in determining fish freshness precisely and conveniently. As future trends, there is a demand for developing applications for consumers to determine fish freshness based on artificial senses.

Combined Effects of Temperature and Dietary Lipid Level on Body Composition, Growth, and Freshness Profile in European Seabass, Dicentrarchus labrax

A fish trial was carried out to evaluate the combined effects of temperature and dietary lipid level on the body composition, growth performance, and freshness profile of the European seabass (Dicentrarchus labrax). Fish were kept for 56 days at 20 °C and 24 °C and fed on two diets, with 16% and 20% lipid. At the end of the trial, fish were euthanized at two temperature conditions (0.6 °C or −0.6 °C) and kept on ice for 10 days at 4 °C to evaluate their freshness condition. Findings demonstrated that fish reared at 24 °C presented a lower lipid level and a higher daily growth index than those at 20 °C. Additionally, sensory analysis (Quality Index Method—QIM) and microbiological analysis revealed that fish reared at 24 °C showed better freshness conditions than those at 20 °C. However, the 16S rRNA metabarcoding analyses revealed a higher proliferation of genera associated with fish-spoiling bacteria in the skin microbiome of fish reared at 24 °C, i.e., Vibrio and Acinetobacter, which was not observed in the skin microbiome of fish reared at 20 °C. Nevertheless, the dietary lipid level did not have any influence on fish freshness. Therefore, our data suggest that the increase in temperature to 24 °C is beneficial for the growth and freshness profile (lower QIM and lower CFUs/cm2) of this particular species. Additionally, the lower euthanasia temperature (−0.6 °C) seems to lead to higher fish freshness than the normal temperature (0.6 °C).

Quality index method developed for raw anglerfish (Lophius piscatorius) stored in ice

The quality index method (QIM) is a widely accepted solution to establish the state of fish freshness quickly and effectively. The present study aims to determine increasingly reliable freshness parameters for fresh and whole Lophius piscatorius stored in ice. Sensory and microbiological analyses were performed on 148 anglerfishes. Sensory evaluations were performed based on the QIM, updating a previously proposed quality index (QI) scheme. Total viable count and specific spoilage organisms were determined through microbiological analyses of the tail musculature, evaluating their correlations with the QI scores over time. The updated QI scheme included 3 characters, namely appearance, eye, and fin, for a total of 18 demerits points. A positive linear correlation between QI score and storage time was observed such that the sensory rejection time (8th day) can be predicted within ± 1 day with the developed scheme. At the sensory rejection point, loads of the spoilage microbial flora were not high enough to be relatable to the appreciated alterations probably due to the anglerfish morphology in which the tail musculature is isolated from the gills and viscera, the main sources of bacterial contamination. The proposed scheme offers a ready-to-use freshness assessment of the anglerfish although further validations are needed.

Effects of Konjac Glucomannan/ε-Polylysine Hydrochloride/Ferulic Acid Composite Coating on the Freshness Preservation Performance and Flavor of Refrigerated Sea Bass Fillets

Coating preservation has a remarkable effect on the preservation of aquatic products. This work prepared a composite coating using konjac glucomannan (KGM) as the film-forming matrix and ε-polylysine hydrochloride (ε-PL) and ferulic acid (FA) as the preservative. Three types of treated sea bass (KGM, KGM-ε-PL, and KGM-ε-PL-FA) and untreated sea bass were stored at 4 °C for 20 days to compare freshness changes under different treatment conditions. The results showed that the surface color and texture of sea bass in refrigerated storage changed dramatically and deteriorated as storage time increased. The composite coating treatment was significantly different from the control group. Using Gas-phase ion migration spectrometry (GC-IMS) technology, 32 volatile compounds, such as aldehydes, alcohols, and ketones, were found in fillets during flavor quality analysis. The composite coating can successfully inhibit the formation of odor compounds such as 2-nonenone, isoamyl alcohol monomer, ammonia, and trimethylamine, delaying the deterioration of fish and improving freshness. Among them, KGM-ε-PL-FA composite coating has the most remarkable preservation performance, which significantly inhibits the occurrence of rotten odor, and has a potential application prospect in the field of food preservation.

On the validity of longitudinal comparisons of central location consumer testing results prior to COVID-19 versus home use testing data during the pandemic

Consumer testing assays a panel's liking of a food or other sensory stimulus. However, liking can be influenced by mood, with people feeling more uncomfortable, or more unhappy reporting lower liking ratings than those in a higher affect. Though consumer testing typically takes place as a central location test (CLT, usually in a set of standardized sensory booths), the COVID-19 pandemic has resulted in a global pivot to home use tests (HUTs), where panelists can taste and smell samples unmasked more safely while in their own homes. Unfortunately, as this situation differs in many ways to a central location test, this puts the validity of longitudinal comparisons of liking scores under question. Further, as people across the globe report feelings of worry, unease, and stress during the pandemic, this may present a second source of variation in affect with previous years. We tested a set of snack bar samples both at home and in a central location, in repeated measures with the same panel, to test the validity of comparisons across locations. We further compared CLT results to those when testing the same samples in a previous year. Finally, we performed a meta-analysis of existing data on this subject. While liking behavior in CLTs did not differ between years, panelists rated some samples higher when in their own homes, in line with results from the meta-analysis of previous reports. Interestingly, panelists in the study also assigned fewer penalties in the HUT, implying a less analytical mindset when in the home. Results suggest that care should be taken when comparing results taken at home during the COVID-19 pandemic to those taken previously in a central location. PRACTICAL APPLICATION: Consumer testing is applied in the food industry to evaluate a panelist's liking for a food product or stimulus. However, liking is also dependent on factors extrinsic to the samples tested. Thus, with the switch to in-home testing due to COVID-19, we compared liking scores from in-home and central locations testing, with higher scores common in HUTs.

Sensory evaluation of fresh/frozen mackerel products: A review

Mackerel has received considerable attention in the global food market as one of the most important pelagic commercial fish species. The quality of mackerel is influenced by species, season, fishing area, nutritional status, catching method, handling, and storage. Due to the mackerel's perishability, its quality is mainly measured by sensory procedures. Although considerable effort has been made to explore quick and reliable quality analysis, developing a practical and scientific sensory evaluation of mackerel has been an active ongoing study area to meet the quality evaluation demand of the industry. Different sensory evaluation methods have been used to assess the mackerel fish quality, including Palatability and Spoilage test, Torry scheme, EU scheme, Quality Index Method, Catch damage index and Processed fish damage index, Affective test, Discriminative test, and Descriptive test. Each method has its strength and weakness. Despite mackerel sensory evaluation protocols having undergone partial harmonization, specific sample process needs to be carefully followed to minimize the change during sample preparation. This review summarizes the sensory evaluation methods in mackerel research, the factors affecting sensory evaluation, and then updates the latest advances in mackerel sensory evaluation and offers guidance for presenting its application in the mackerel chain. Also, each technique's advantages and limitations are discussed. In our opinion, the future trends for sensory evaluation of mackerel should be consumer-centric.

Quality Assessment of Chilled and Frozen Fish-Mini Review

Fish is a very perishable food and therefore several storage strategies need to be employed to increase its shelf-life, guaranteeing its safety and quality from catch to consumption. Despite the advances in modern fish storage technologies, chilling and freezing are still the most common preservation methods used onboard. The present review aims to summarize strategies to increase the shelf-life of fresh (chilled) and frozen fish, as whole, gutted, or fillet, involving the assessment of different traditional cooling and freezing conditions of different fish species caught in different locations. Although there are other factors that influence the fish shelf-life, such as the fish species and the stress suffered during catch, storage time and temperature and the amount of ice are some of the most important. In addition, the way that fish is stored (whole, fillet, or gutted) also contributes to the final quality of the product. In most studies, whole chilled and frozen fish present longer shelf-life than those preserved as gutted and filleted. However, it should be noted that other factors related to the organism, capture method, and transport to the preparation/processing industry should be considered for shelf-life extension.