Characterization of volatile compounds, physico-chemical and sensory characteristics of smoked dry-cured ham.

Volatile compounds from smoked dry-cured ham were isolated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated for sensory physical and chemical characteristics. Eighty seven volatile aroma compounds of smoked dry-cured ham were identified. Chemical groups identified were aldehydes (35.6%), phenols (34.3%), alcohols (13.8%), terpenes (6.4%), aromatic hydrocarbons (2.6%), alkanes (2.2%), ketones (2.2%), esters (1.7%) and acids (0.7%). Except volatile compounds derived from lipolysis and proteolysis the second most abundant constituents were phenols that originate from smoking phase of the production process. The most abundant phenols were: 4-methylphenol, 3-methylphenol, 2-metoxy-4-methylphenol, 2-methylphenol, 2,6-dimethoxyphenol and 4-ethyl-2 methoxyphenol. Principal components analysis showed that NaCl and ash content positively correlated with the salty taste while fat content was correlated to marbling. Water content and aw value were negatively correlated with hardness of dry-cured ham while phenols were positively corelated with smoky aroma. Due to the different volatile composition and pronounced smoky aroma, smoked dry-cured ham can be distinguished from other types of dry-cured hams.

Assessment of Chitosan/Gelatin Blend Enriched with Natural Antioxidants for Antioxidant Packaging of Fish Oil.

In this research, bio-based films were developed using polyelectrolyte complexes derived from chitosan and gelatin for packaging fish oil. To further enhance the antioxidant functionality, the films were enriched with gallic acid and orange essential oils, either individually or in combination. Initially, the films were characterized for their physico-chemical, optical, surface, and barrier properties. Subsequently, the phenolic compounds and antioxidant capacity of the films were assessed. Finally, the films were tested as antioxidant cover lids for packaging fish oil, which was then stored at ambient temperature for 30 days, with periodical monitoring of oil oxidation parameters. This study revealed that the inclusion of gallic acid-induced possible crosslinking effects, as evidenced by changes in moisture content, solubility, and liquid absorption. Additionally, shifts in the FTIR spectral bands suggested the binding of gallic acid and/or phenols in orange essential oils to CSGEL polymer chains, with noticeable alterations in film coloration. Notably, films containing gallic acid exhibited enhanced UV barrier properties crucial for preserving UV-degradable food compounds. Moreover, formulations with gallic acid demonstrated decreased water vapor permeability, while samples containing orange essential oils had lower CO2 permeability levels. Importantly, formulations containing both gallic acid and essential oils showed a synergistic effect and a significant antioxidant capacity, with remarkable DPPH inhibition rates of up to 88%. During the 30-day storage period, fish oil experienced progressive oxidation, as indicated by an increase in the K232 value in control samples. However, films incorporating gallic acid or orange essential oils as active antioxidants, even used as indirect food contact, effectively delayed the oxidation, highlighting their protective benefits. This study underscores the potential of sustainable bio-based films as natural antioxidant packaging for edible fish oil or fresh fish, offering a promising tool for enhancing food preservation while reducing its waste.

Characterization of Antioxidant Bioactive Compounds and Rheological, Color and Sensory Properties in 3D-Printed Fruit Snacks.

The influence of wheat starch (6%, 8% and 10%, w/w) and a 3D printing program (program 1 vs. program 2) on the content of bioactive compounds, antioxidant capacity, color parameters and rheological and sensory properties was investigated in 3D strawberry and strawberry tree fruit snacks. Increasing the starch content led to a decrease in the content of almost all the bioactive compounds, while it had no effect on the antioxidant capacity. The printing program had no significant effect on the bioactive compounds (except hydroxycinnamic acids), antioxidant capacity and color parameters. A higher starch content improved the strength of the sample but had no effect on the mechanical properties. Smaller particles with a higher starch content improved the stability of the sample. In contrast to the programs, varying the starch content had a significant effect on all the color parameters except the a* values. Eight different sweeteners in two different concentrations were used for the sensory evaluation of the 3D-printed snacks. The variations in sweetener content only affected the sweet and harmonious taste. In summary, this study confirms the great potential of fruit bases for the production of 3D-printed snacks with excellent biological and rheological properties, which can be a step toward personalized food with the addition of sweeteners.

Influence of Fish Handling Practices Onboard Purse Seiners on Quality Parameters of Sardines (Sardina pilchardus) during Cold Storage.

Small pelagic fish are a rich source of high-quality proteins and omega-3 fatty acids, but they are highly perishable due to the activity of microorganisms, endogenous enzymes, and oxidation processes that affect their muscle tissues during storage. This study focused on analyzing the influence of fish handling practices onboard vessels on sensory quality attributes, pH, water holding capacity, TVB-N, proteolytic changes, and lipid oxidation in sardine muscle tissue during cold storage. Experiments were conducted onboard fishing vessels during regular work hours, with added consistency, accounting for similar sardine sizes (physiological and reproductive stages) under similar environmental conditions. Traditional handling practices, e.g., boarding the catch with brail nets and transporting the fish in plastic crates with flake ice, were compared with the use of modified aquaculture pumps for boarding the catch and transporting it in isothermic boxes submerged in ice slurry. Results confirmed significant differences in the parameters among the different fishing vessels, although no significant differences were found between the two methods of fish handling on board the vessels. The study also confirmed a higher rate of lipid oxidation in fish muscle due to physical damage and an increased degree of proteolysis in samples with lower muscle pH values.

Effect of seasonal temperature shifts on body homeostasis, biochemical parameters and chemical composition of green ormer (Haliotis tuberculata) in the Northern Adriatic.

Seasonal responses of green ormer in terms of antioxidant capacity and lipid peroxidation, proximate and fatty acid tissue composition, trace and macro elements concentrations over the seasons were studied in relation to temperature shifts in the Northern Adriatic Sea. Overall antioxidative defenses (SOD, TBARS, TAS, LDH) varied significantly (p < 0.001) according to seasons (primarily spring and summer). The proportions of overall SFA were highest in summer. The proportions of MUFA increased in autumn, with significant differences between genders in spring and summer, and spring, summer and autumn for C18:1n7 and C20:4n6. The only fatty acid lacking significant variation between seasons was C22:5n3. Significant overall differences were observed in summer vs. winter samples for As, Ba, Co, Ni, Mn, Pb, Sb, and Se content in soft tissues, however, gender variations were not significant. The data obtained in the study are of utmost importance for the management of this under-investigated species.

Influence of Sample Matrix on Determination of Histamine in Fish by Surface Enhanced Raman Spectroscopy Coupled with Chemometric Modelling.

Histamine fish poisoning is a foodborne illness caused by the consumption of fish products with high histamine content. Although intoxication mechanisms and control strategies are well known, it remains by far the most common cause of seafood-related health problems. Since conventional methods for histamine testing are difficult to implement in high-throughput quality control laboratories, simple and rapid methods for histamine testing are needed to ensure the safety of seafood products in global trade. In this work, the previously developed SERS method for the determination of histamine was tested to determine the influence of matrix effect on the performance of the method and to investigate the ability of different chemometric tools to overcome matrix effect issues. Experiments were performed on bluefin tuna (Thunnus thynnus) and bonito (Sarda sarda) samples exposed to varying levels of microbial activity. Spectral analysis confirmed the significant effect of sample matrix, related to different fish species, as well as the extent of microbial activity on the predictive ability of PLSR models with R2 of best model ranging from 0.722-0.945. Models obtained by ANN processing of factors derived by PCA from the raw spectra of the samples showed excellent prediction of histamine, regardless of fish species and extent of microbial activity (R2 of validation > 0.99).

Determination of histamine in fish by Surface Enhanced Raman Spectroscopy using silver colloid SERS substrates.

This study was focused on development of a rapid and sensitive method for histamine determination in fish based on Surface Enhanced Raman Spectroscopy (SERS) using simple and widely available silver colloid SERS substrate. Extraction of histamine with 0.4M perchloric acid and purification with 1-butanol significantly shortened sample preparation (30min) and provided clear SERS spectra with characteristic Raman bands of histamine. Principal component analysis effectively distinguished SERS spectra of fish samples with different histamine content. Partial least square (PLS) regression models confirmed reliability of detection and spectral analysis of histamine with SERS. In histamine concentration range 0-200mgkg-1, significant in legislative and fish quality control aspects, PLS regression model based on spectral range 1139.9-1643.7cm-1 showed linear trend with R2pred=0.962, RPD=7.250. Presented protocol for histamine extraction and purification followed by SERS analysis coupled with chemometric approach, enabled development of rapid and inexpensive method for histamine determination in fish.

Determination of volatile compounds and quality parameters of traditional Istrian dry-cured ham.

The aim of this work was to determine the characteristics of Istrian dry-cured ham by instrumental methods and sensory analysis. The aroma-active compounds of Istrian dry-cured ham from 2010 and 2012 were investigated by using headspace-solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics. 92 volatile aroma compounds of Istrian dry-cured ham were found. Volatile compounds belonged to several chemical groups: aldehydes (51.4; 51.3%), terpenes (16.5; 16.4%), alcohols (15.5; 13.2%), ketones (8.6; 7.4%), alkanes (3.8; 5.7%), esters (1.3; 1.6%), aromatic hydrocarbons (0.8; 3.9%) and acids (0.6; 0.9%). Principal component analysis (PCA) showed that fat content, tenderness and melting texture were positively correlated. Terpenes were strongly correlated with flavour of added spices. Sweet taste and the presence of esters were positively correlated as well as negative odour, raw meat flavour and water content.