A highly pH-responsive gelatin film incorporating purple cabbage anthocyanin (PCA) and chondroitin sulphate (CS)/tannic acid (TA) was developed. Co-pigmentation of PCA via CS/TA improved its photothermal stability and visibility of color change in gelatin film. The morphological and structural properties of CS-PCA and TA-PCA films revealed that a more stable network was formed as new hydrogen bonds were generated by the co-pigmentation. Meanwhile, the co-pigmentation improved film's mechanical and hydrophobic properties, expressed as higher tensile strength (16.65 and 17.97 Mpa) and lower water vapor permeability (1.45 and 1.41) in CS-PCA and TA-PCA films, compared to PCA film. CS-PCA and TA-PCA films showed distinct color transitions for chilled fish fillets during storage. Total color difference (ΔE) of CS-PCA and TA-PCA films correlated well with the deterioration indexes of total volatile base nitrogen (TVB-N). All the results provided a novel pH-sensitive intelligent packaging strategy by co-pigmenting CS/TA with PCA for freshness monitoring.

• Klíčová slova
• Anthocyanin, Co-pigmentation, Enhanced recognition accuracy, Sub-freshness monitoring, pH-sensitive film,
• Publikační typ
• časopisecké články MeSH

In the study, high internal phase emulsions (HIPEs) prepared from Antarctic krill oil (AKO) were added into surimi and the effects on gel properties, lipid quality and stability were investigated. It is found that HIPEs-added groups exhibited higher gel strength and lower cooking loss than Oil-added counterparts. HIPEs-added groups had higher proportion of capillary water, and microstructure of HIPEs-added gels showed fewer large voids and small size droplets. HIPEs-added groups also showed less pronounced myosin heavy chain band. HIPEs- and Oil-added gels showed > 3500 mg/kg EPA + DHA and 0.4-0.8 mg/kg astaxanthin, and most HIPEs-added groups had higher levels of them but lower TBARS values. Results suggest AKO-HIPEs could reduce the intervention by lipids on myosin crosslinking during gelation, and protect fatty acids and asxtanthin from oxidation due to oxygen-isolation led by their high accumulation. Thus, AKO-HIPEs can be applied to fortify ω-3 PUFA and maintain good gel properties in surimi product.

• Klíčová slova
• Antarctic krill oil, High internal phase emulsion, Surimi, TBARS, ω-3 PUFA,
• MeSH
• emulze chemie   MeSH
• Euphausiacea * chemie   MeSH
• gely MeSH
• kyseliny mastné omega-3 * MeSH
• mastné kyseliny chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• emulze MeSH
• gely MeSH
• kyseliny mastné omega-3 * MeSH
• mastné kyseliny MeSH

A pH-sensitive intelligent film was prepared using gelatin as base substrate and purple cabbage anthocyanins (PCA) as indicator with the aid of ultrasound. Fourier transforms infrared and X-ray diffraction analysis showed that 600 W ultrasound brought changes to characteristic bands of gelatin and PCA, and flattened diffraction peak around 2θ = 20°. Film prepared with 600 W ultrasound exhibited high tensile strength and elongation at break and showed high transition temperature and surface hydrophobicity by differential scanning calorimetry and contact angle analysis. The incorporation of <0.35 % PCA had no effect on mechanical properties of films, but it improved the antioxidative activity. Films with 0.14 %, 0.21 % and 0.28 % PCA suggested pronounced color difference at pH 5-8, in accordance with the sharp ΔE difference. Films with 0.28 % PCA was applied for monitoring chilled-stored fish quality. It showed visible color change from pink to atrovirens during storage. The difference of ΔE at various days was ≥5 and ΔE highly correlated with total volatile basic nitrogen. Therefore, gelatin along with PCA under appropriate ultrasound treatment could prepare intelligent film to preserve and monitor the quality of chilled-stored fish.

• Klíčová slova
• Color response, FTIR, XRD,
• MeSH
• anthokyaniny * chemie   MeSH
• Brassica * MeSH
• koncentrace vodíkových iontů MeSH
• obaly potravin MeSH
• želatina chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anthokyaniny * MeSH
• želatina MeSH

BACKGROUND: Omega-3 common carp (OCC) raised by patented culture systems have higher level of n-3 fatty acids and n-3/n-6 ratio than normal common carps (NCCs) from traditional culture system. Whether the patented farming system and modified fatty acid profile will influence OCC storage stability is unclear. This study aimed to expose the differences of post-mortem quality changes between NCC and OCC. RESULTS: NCC and OCC have similar rigor mortis patterns, only a higher level of lactic acid was observed in NCC after 96 h. Adenosine triphosphate (ATP) related compounds had no major differences, but slightly higher inosine monophosphate in OCC was found at 36 h. The K-value, Ki-value and Hx-index demonstrated high cohesiveness (Pearsons two-tailed, r = 0.968-0.984, P < 0.05) during storage, with statistically comparable (P > 0.05) temporal progress of change in NCC and OCC. The indices were lower in OCC than in NCC. Attenuation of myosin heavy chain in OCC was not as distinct as in NCC, coincided with its higher salt-soluble protein level at 144 h. Before 96 h, thiobarbituric acid value (TBA), total viable count (TVC), cooking loss (CL), drip loss (DL), and hardness in NCC and OCC were similar. However, at 144 h, higher TBA, TVC, CL and DL while lower hardness in NCC than in OCC were observed. Principle component analysis showed good separation of NCC and OCC in biplot at 0 and 144 h. CONCLUSION: Patented culture system has a slightly positive influence on post-mortem quality of common carp. It can be used for producing OCC without compromising storage stability. © 2020 Society of Chemical Industry.

• Klíčová slova
• ATP related compounds, common carp, lipid oxidation, protein degradation, rigor mortis,
• MeSH
• adenosintrifosfát analýza   MeSH
• kapři klasifikace   růst a vývoj   MeSH
• nízká teplota MeSH
• potrava z moře (živočišná) analýza   MeSH
• řízení kvality MeSH
• skladování potravin MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• adenosintrifosfát MeSH

Effects of 0, 1, 5, 25 and 125 μmol/g gallic acid (GA) without or with ultrasound treatment (20 kHz, 400 w, 5 min) (NU or U groups) on properties of Japanese seerfish myofibrillar protein (MP) were studied. After sonication, tryptophan fluorescence decreased while surface hydrophobicity, free amine and SH content (not U125) and solubility increased. After heating, NU125 showed the heaviest polymers among NU groups, but U5 exhibited the strongest while U125 showed the weakest polymers in U groups. Storage modulus (G') of NU groups showed a dose-dependent style, but for U groups, U5 had the highest G' while U125 had the lowest G'. Mass analysis confirmed the formation of Cys-GA-Cys and Lys-GA-Lys polymers in U125. Thus, ultrasound promoted structural unfolding and reactive groups exposure, producing GA quinone by triggering OH·. These together led to the G' improvement by low dose GA but deterioration by high does GA.

• Klíčová slova
• 2,4,6-Trinitrobenzenesulfonic acid (PubChem CID: 11045), 5,5′-Dithiobis-(2-nitrobenzoic acid) (PubChem CID: 6254), Amino-quinone adduct, Bromophenol blue (PubChem CID: 8272), Gallic acid, Gallic acid (PubChem CID: 370), Hydroxyl radical, Maleic acid (PubChem CID: 444266), Myofibrillar protein, N-Ethylmaleimide (PubChem CID: 4362), Rheological properties, Sodium dodecyl sulfate (PubChem CID: 3423265), Thiol-quinone adduct, Ultrasound, l-Leucine (PubChem CID: 6106), β-Mercaptoethanol (PubChem CID: 1567),
• MeSH
• hydrofobní a hydrofilní interakce MeSH
• kyselina gallová chemie   MeSH
• rybí proteiny chemie   MeSH
• ultrazvuk MeSH
• velikost částic MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina gallová MeSH
• rybí proteiny MeSH