Comparative human-sensory evaluation and quantitative comparison of odour-active oxidation markers of encapsulated fish oil products used for supplementation during pregnancy and the breastfeeding period

The aroma transformation of Japanese sea bass (Lateolabrax japonicas) through endogenous enzyme incubation during the lag phase of attached microorganisms

Endogenous enzymes play a crucial role in determining fish product aroma. However, the attached microorganisms can promote enzyme production, making it challenging to identify specific aromatic compounds resulting from endogenous enzymes. Thus, we investigated the aroma transformation of Japanese sea bass through enzymatic incubation by controlling attached microorganisms during the lag phase. Our results demonstrate that enzymatic incubation significantly enhances grassy and sweet notes while reducing fishy odors. These changes in aroma are associated with increased levels of 10 volatile compounds and decreased levels of 3 volatile compounds. Among them, previous studies have reported enzyme reaction pathways for octanal, 1-nonanal, vanillin, indole, linalool, geraniol, citral, and 6-methyl-5-hepten-2-one; however, the enzymatic reaction pathways for germacrene D, beta-caryophyllene, pristane, 1-tetradecene and trans-beta-ocimene remain unclear. These findings provide novel insights for further study to elucidate the impact of endogenous enzymes on fish product aromas.

Effects of Bacterioruberin-Rich Haloarchaeal Carotenoid Extract on the Thermal and Oxidative Stabilities of Fish Oil

This study aimed to assess the efficacy of a bacterioruberin-rich carotenoid extract (HAE) derived from the halophilic archaea Halorubrum ezzemoulense DSM 19316 in protecting crude fish oil against thermal oxidation. The research used fish oil derived from anchovies, which had a peroxide value (PV) of 6.44 ± 0.81 meq O2 kg-1. To assess the impact of HAE on the thermal stability and post-oxidation characteristics of fish oil, several concentrations of HAE were added to the fish oil samples: 0 ppm (no additive) (HAE0), 50 ppm (HAE50), 100 ppm (HAE100), 500 ppm (HAE500), and 1000 ppm (HAE1000). Furthermore, a control group was established with the addition of 100 ppm butylated hydroxytoluene (BHT100) in order to evaluate the effectiveness of HAE with a synthetic antioxidant that is commercially available. Prior to the fast oxidation experiment, thermogravimetric analysis was conducted on samples from all experimental groups. At the conclusion of the examination, it was seen that the HAE500 and HAE1000 groups exhibited a delay in the degradation temperature. The experimental groups underwent oxidation at a temperature of 55.0 ± 0.5 °C for a duration of 96 h. The measurement of PV was conducted every 24 h during this time. PV in all experimental groups exhibited a time-dependent rise (p < 0.05). However, the HAE500 group had the lowest PV measurement at the conclusion of the 96 h period (p < 0.05). Significant disparities were detected in the fatty acid compositions of the experimental groups at the completion of the oxidation experiment. The HAE500 group exhibited the highest levels of EPA, DHA, and ΣPUFA at the end of oxidation, with statistical significance (p < 0.05). Through the examination of volatile component analysis, specifically an oxidation marker, it was shown that the HAE500 group exhibited the lowest level of volatile components (p < 0.05). Consequently, it was concluded that the addition of HAE to fish oil provided superior protection compared to BHT at an equivalent rate. Moreover, the group that used 500 ppm HAE demonstrated the highest level of performance in the investigation.

Texture, sensory properties and functionality of extruded snacks from pulses and pseudocereal proteins

BACKGROUND

The protein-rich fractions of pulses and pseudocereals exhibit a well-balanced amino acid profile, particularly when combined in different portions, and are therefore high-value ingredients for the production of extruded snacks. However, the impact of a combination of pulses and pseudocereals on the physical and sensory qualities of extruded snacks has not been investigated up to now. Native or preconditioned protein isolates and concentrates from pulses - as single ingredients or in combination with protein-rich flours of pseudocereals - were analyzed regarding their thermal and functional properties in relation to extrusion characteristics. Low moisture extrusion cooking was used to investigate the impact of protein source (lentil, lupin, faba bean), pseudocereal source (quinoa, amaranth, buckwheat) and protein content (30%, 50%, 70%) on sectional expansion, specific hardness, density and sensory properties of the snacks.

RESULTS

With increasing protein content from 30% to 50%, the sectional expansion decreased and the density and specific hardness of the extrudates increased, which could be counteracted by preconditioning of the protein-rich ingredients. Lupin protein-based extrudates exhibited satisfactory texture and sensory properties. Extruded mixtures of pulses and pseudocereals (70% protein) exhibited a smaller sectional expansion compared to pulses as single ingredients (30%, 50%), regardless of pseudocereal type. However, the texture and sensory properties of the extruded blends were satisfactory.

CONCLUSIONS

We show for the first time that protein-rich fractions of pulses and pseudocereals can be processed into expanded snacks with favorable texture and nutritional properties such as increased protein contents (70%) and balanced amino acid profiles. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Application of Plackett-Burman Design in Screening of Natural Antioxidants Suitable for Anchovy Oil

Considering the safety of synthetic antioxidants, more and more natural antioxidants have been developed and utilized in foods. This study aimed to screen out a natural antioxidant combination from many antioxidants, which could significantly affect the oxidation stability of anchovy oil, while Plackett–Burman design (PBD) methodology was employed in this screening. According to the statistical results of this design, sesamol, dihydromyricetin, teapolyphenol, and rosemary acid were four significant parameters on the oxidation stability of anchovy oil. Moreover, dihydromyricetin presented the best antioxidant effect among nine kinds of selected antioxidants when they were used alone in anchovy oil. Meanwhile, a combination including sesamol (0.02%), teapolyphenol (0.02%). and rosemary acid (0.02%) was adopted, and its antioxidant ability was similar to that of tert-butylhydroquinone (TBHQ). Additionally, phytic acid as a synergist was used and combined with sesamol, and the antioxidant ability of this combination was better than that of TBHQ. This study presented a reference for the industrial applications of natural antioxidants and synergists in anchovy oil.

Assessment of main factor causing sensory quality defects in chicken seasoning during storage

BACKGROUND

Chicken seasoning is a widely consumed palatable seasoning made with chicken meat. Quality, and especially sensory quality, may determine the consumer choice of food. The same bag of chicken seasoning will be stored by the consumers over a long period of time when it is in use, so it is particularly important to be able to assess its sensory quality. However, the sensory quality defects of chicken seasoning during storage remain unknown. This study evaluated flavor changes in chicken seasoning during storage using sensory evaluation and gas chromatography-mass spectrometry (GC-MS).

RESULTS

The sensory evaluation indicated a perceptible change in rancidity during storage. The GC-MS results showed increases in the content of aldehydes, heterocyclic compounds, ketones, and sulfur compounds associated with lipid oxidation. A random forest model was constructed to predict the storage time based on the data for volatile compounds related to lipid oxidation. The low average predicted error indicated a good correlation between lipid oxidation and storage time.

CONCLUSION

These results suggest that lipid oxidation is the main factor behind sensory quality defects in chicken seasoning during storage. This can be used as the basis for further evaluation of sensory quality and the shelf life of chicken seasoning. © 2018 Society of Chemical Industry.

Characterization of odorous contaminants in post-consumer plastic packaging waste using multidimensional gas chromatographic separation coupled with olfactometric resolution

The increasing world population with their growing consumption of goods escalates the issue of sustainability concepts with increasing demands in recycling technologies. Recovery of post-consumer packaging waste is a major topic in this respect. However, contamination with odorous constituents currently curtails the production of recycling products that meet the high expectations of both consumers and industry. To guarantee odor-free recyclates, the main prerequisite is to characterize the molecular composition of the causative odorants in post-consumer plastic packaging waste. However, targeted characterization of odorous trace contaminants among an abundance of volatiles is a major challenge and requires specialized and high-resolution analytical approaches. For this aim, post-consumer packaging waste was characterized by sensory analysis and two-dimensional high resolution gas chromatography coupled with mass spectrometry and olfactometry. The 33 identified odorants represent various structural classes as well as a great diversity of smell impressions with some of the compounds being identified in plastics for the first time. Substances unraveled within this study provide insights into sources of odorous contamination that will require specific attention in the future in terms of screening and prevention in recycling products.

Characterisation of aroma-active and off-odour compounds in German rainbow trout (Oncorhynchus mykiss). Part I: Case of aquaculture water from earthen-ponds farming

Comprehensive analyses were accomplished to explore the odorous molecules responsible for off-odour development in earthen-ponds rainbow trout (Oncorhynchus mykiss) aquaculture farming in Germany. In this part of the study, water odorants were extracted using solvent-assisted flavour evaporation (SAFE); then, extracts were analysed by one- and two- dimensional high resolution gas chromatography coupled with olfactometry and mass spectrometry using two columns with different polarity (DB-FFAP and DB-5). Aroma extract dilution analysis (AEDA) of the solvent extract samples revealed 54 odorants, and 47 of them were identified. In this study, a series of compounds is described for the first time in German earthen-ponds rainbow trout aquaculture water including, amongst others, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol), vanillin, (E)-4,5-epoxy-(E)-2-decenal, 4-ethyloctanoic acid, 3-methylindole (skatole), 5α-androst-16-en-3-one (androstenone), and 2-(2-butoxyethoxy) ethanol. Moreover, the sensory experiment indicated that (E)-4,5-epoxy-(E)-2-decenal, (E,E)-2,4-octadienal, and 1-octen-3-one are the main contributors to the metallic, cucumber, and mushroom notes of the samples.

Physicochemical and sensory characterization of refined and deodorized tuna (Thunnus albacares) by-product oil obtained by enzymatic hydrolysis

In this study, the effects of chemical refining and deodorization on fatty acid profiles and physicochemical and sensory characteristics of the tuna by-product oil obtained by enzymatic hydrolysis were evaluated. Enzymatic extraction was conducted for 120 min at 60 °C and pH 6.5 using Alcalase at an enzyme-substrate ratio of 1:200 w/w. The chemical refining of crude oil consisted of degumming, neutralization, washing, drying, bleaching, and deodorization; deodorization was conducted at different temperatures and processing times. Although chemical refining was successful, temperature and chemical reagents favored the removal of polyunsaturated fatty acids (PUFA) from the oil. Aroma attributes of fishy odor, frying odor, and rancid odor predominantly contributed to the sensory evaluation of the product. Deodorization conditions of 160 °C for 1h and 200 °C for 1h were recommended for the tuna by-product oil, which is rich in PUFA.

Off-flavour masking of secondary lipid oxidation products by pea dextrin

The aim of the present study was to evaluate the off-flavour masking potential of pea dextrin (PD) in emulsions rich in ω-3 and ω-6-fatty acids in comparison with maltodextrin (MD) and 2-hydroxypropyl-β-cyclodextrin (HPBCD). After optimisation of the homogenisation procedure, stable emulsions were prepared and stored for up to eight weeks. The development of six secondary lipid oxidation products: propanal, 1-penten-3-one, 1-penten-3-ol, hexanal, (E,E)-2,4-heptadienal and (E,Z)-2,6-nonadienal, was monitored via headspace gas chromatography after solid-phase microextraction. Sensory evaluation of the emulsions was performed by a trained panel. PD already showed masking properties for propanal, 1-penten-3-one, hexanal and (E,E)-2,4-heptadienal during validation of the gas chromatographic analysis, but not for 1-penten-3-ol or (E,Z)-2,6-nonadienal. During storage, the course of lipid oxidation was similar in all emulsions as concluded from the hydroperoxide value. Results from the sensory evaluation confirmed a masking of rancid off-flavour. In conclusion, pea dextrin is suitable for masking off-flavour resulting from early stages of lipid oxidation.

Comparative Evaluation of Diagnostic Tools for Oxidative Deterioration of Polyunsaturated Fatty Acid-Enriched Infant Formulas during Storage

The challenge in the development of infant formulas enriched with polyunsaturated fatty acids (PUFAs) is to meet the consumers' expectations with regard to high nutritional and sensory value. In particular, PUFAs may be prone to fatty acid oxidation that can generate potential rancid, metallic and/or fishy off-flavors. Although such off-flavors pose no health risk, they can nevertheless lead to rejection of products by consumers. Thus, monitoring autoxidation at its early stages is of great importance and finding a suitable analytical tool to perform these evaluations is therefore of high interest in quality monitoring. Two formulations of infant formulas were varied systematically in their mineral composition and their presence of antioxidants to produce 18 model formulas. All models were aged under controlled conditions and their oxidative deterioration was monitored. A quantitative study was performed on seven characteristic odor-active secondary oxidation products in the formulations via two-dimensional high resolution gas chromatography-mass spectrometry/olfactometry (2D-HRGC-MS/O). The sensitivity of the multi-dimensional GC-MS/O analysis was supported by two additional analytical tools for monitoring autoxidation, namely the analysis of lipid hydroperoxides and conjugated dienes. Furthermore, an aroma profile analysis (APA) was performed to reveal the presence and intensities of typical odor qualities generated in the course of fatty acid oxidation. The photometrical analyses of lipid hydroperoxides and conjugated dienes were found to be too insensitive for early indication of the development of sensory defects. By comparison, the 2D-HRGC-MS/O was capable of monitoring peroxidation of PUFAs at low ppb-level in its early stages. Thereby, it was possible to screen oxidative variances on the basis of such volatile markers already within eight weeks after production of the products, which is an earlier indication of oxidative deterioration than achievable via conventional methods. In detail, oxidative variances between the formulations revealed that lipid oxidation was low when copper was administered in an encapsulated form and when antioxidants (vitamin E, ascorbyl palmitate) were present.