53 research outputs found
Freshness evaluation of grass carp (Ctenopharyngodon idellus) by electronic nose
No full textA novel grass carp (Ctenopharyngodon idellus) freshness rapid evaluation method using electronic nose (EN) was proposed in this paper. Total viable counts (TVC) and gas chromatography-mass spectrometry (GC–MS) were examined. EN responses to grass carp samples stored at 4 °C were continuously measured for 8 days. Microbial growth model was developed based on modified Gompertz regression. Results of TVC and GC–MS provided freshness references for EN analysis. Principal component analysis (PCA) and stochastic resonance (SR) were utilized in EN measurement data analysis. PCA qualitatively discriminated grass carp samples in different freshness. SR output signal-to-noise ratio (SNR) eigenvalues (SNRmax) quantitatively discriminated freshness for all samples. Grass carp freshness evaluation model was developed by non-linear regression between SNRmax values and storage time. Validation experiments results demonstrated that the proposed grass carp freshness rapid evaluation method presented good forecasting accuracy. The proposed method is promising in aquatic product freshness analysis
Polysaccharide impregnation: a pretreatment method for improving scallop quality and flavor
No full textThe quality and flavor of scallops changes during the fresh dry rehydration process. In order to control the changes after rehydration, a scallop pretreatment method was adopted. The pretreatment method involved impregnating fresh scallops with 0.2 g/100 mL konjac glucomannan (KGM), carrageenan (CA), and sodium alginate (SA) before the drying and rehydration process. After rehydration, the KGM treated samples had better water retention and the highest betaine content. The CA treated samples had a deepened yellow color and the highest content of flavoring amino acids (FAA) and inosine monophosphate (IMP). What's more, a total of 77 volatile compounds were detected, with a maximum of 15 esters. The highest proportion in the four groups was eugenol, followed by n-hexadecanoic acid, methyl hexadecanoate etc. The SA group had no significant contribution in terms of quality and taste. The samples pretreated with KGM had the best quality, and those pretreated by CA had the best flavor
The influence of packaging on the time evolution of red wine
No full textWith the aim to determine the influence of packaging in preserving the quality of wine, in this research project the time evolution of a young red wine stored in different packaging materials (glass bottles provided with different closures and Tetrabrik®) and different volumes (2 volumes for each packaging) has been examined by chemical and sensory evaluations, over a period of 12 months. For each packaging solution two different temperature levels (4±1° and 20±1°C) were also maintained throughout the storage period.
Among all the adopted experimental conditions, the rate of wine aging was higher when the volume of the containers decreased and storage temperature increased. Furthermore, the glass bottles generally better preserved wine from oxidation than multilayer materials, regardless of the closure characteristics
Characterization of the Flavor Profile of Bigeye Tuna Slices Treated by Cold Plasma Using E-Nose and GC-IMS
No full textTo avoid heat, treatment induces numerous physicochemical changes under severe conditions in the tuna, cold plasma (CP), as a non-thermal technology, possess objective potential on tuna processing. The effect of cold plasma on the volatile flavor compounds of bigeye tuna (Thunnus obesus) sashimi has been evaluated using electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS). GC–IMS results revealed a total of 33 volatile compounds in tuna slices. The effect of CP treatment on tuna flavor was not significant, furthermore CP could protect volatile freshness compounds such as 1-hexanol. Principal component analysis (PCA) of the E-nose and GC–IMS results could effectively differentiate the effect of storage to tuna sashimi. There was a high correlation between the E-nose and GC–IMS results, providing a theoretical basis for establishing the flavor fingerprint of tuna sashimi
Antibacterial mechanism of atmospheric cold plasma against Pseudomonas fluorescens and Pseudomonas putida and its preservation application on in-packaged red shrimp paste
No full textCharacterization and Application in Packaging Grease of Gelatin–Sodium Alginate Edible Films Cross-Linked by Pullulan
No full textGelatin–sodium alginate-based edible films cross-linked with pullulan were prepared using the solution casting method. FTIR spectroscopy demonstrated the existence of hydrogen bonding interactions between the components, and scanning electron microscopy observed the component of the films, revealing electrostatic interactions and thus explaining the differences in the properties of the blend films. The best mechanical properties and oxygen barrier occurred at a 1:1 percentage of pullulan to gelatin (GP11) with sodium alginate dosing for modification. Furthermore, GP11 demonstrated the best thermodynamic properties by DSC analysis, the highest UV barrier (94.13%) and the best oxidation resistance in DPPH tests. The results of storage experiments using modified edible films encapsulated in fresh fish liver oil showed that GP11 retarded grease oxidation by inhibiting the rise in peroxide and anisidine values, while inappropriate amounts of pullulan had a pro-oxidative effect on grease. The correlation between oil oxidation and material properties was investigated, and water solubility and apparent color characteristics were also assessed
Surface Modification via Dielectric Barrier Discharge Atmospheric Cold Plasma (DBD–ACP): Improved Functional Properties of Soy Protein Film
No full textAtmospheric cold plasma (ACP), a novel technology, has been widely adopted as an efficient approach in surface modification of the film. The effect of ACP treatment on the physicochemical and structural properties of soy protein film were investigated. As a result, the optimal conditions for the preparation of the film were determined for soy protein (10%), glycerol (2.8%), ACP treatment at 30 kV for 3 min, on the basis of elongation at the break, and water vapor permeability. Under the optimal conditions, the ACP–treated films exhibited enhanced polarity according to the increased values of solubility, swelling index, and moisture content, compared with the untreated counterpart. An increase in the hydrophilicity is also confirmed by the water contact angle analysis, which decreased from 87.9° to 77.2° after ACP pretreatment. Thermostability was also improved by ACP exposure in terms of DSC analysis. SEM images confirmed the tiny pores and cracks on the surface of film could be lessened by ACP pretreatment. Variations in the Fourier transform infrared spectroscopy indicated that some hydrophilic groups were formed by ACP pretreatment. Atomic force microscopy data revealed that the roughness of soy protein film which was pretreated by ACP was lower than that of the control group, with an Rmax value of 88.4 nm and 162.7 nm for the ACP- treated and untreated samples, respectively. The soy protein film was characterized structurally by FT–IR and DSC, and morphological characterization was done by SEM and AFM. The soy protein film modified by ACP was more stable than the control group. Hence, the great potential in improving the properties of the film enables ACP treatment to be a feasible and promising alternative to other modification methods
Re: Global inequities in dietary calcium intake during pregnancy: a systematic review and meta‐analysis
No full text) by adding Fe (II) chelating hairtail protein hydrolysates (Fe (II)‐HPH) to the feed
No full textTo study the effect on amino acid and mineral content of the loach meat by adding Fe (II) chelating hairtail protein hydrolysates (Fe (II)-HPH) to the feed. A total of 100 healthy loaches were selected. After 1 week's adaptive feeding, they were randomly divided into five groups and fed with feeds containing of Fe (II)-HPH (0, 0.5, 1, 2, and 4 g/kg). On the 40th day, detection work of general nutrients (moisture, ash, crude protein, and crude fat), mineral elements (Fe, Mn, Cu, Zn, Na, K, and Ca), amino acid and amino acid score (AAS), Chemical Score (CS) and essential amino acid index (EAAI) indexes were done. The results show that crude protein has the highest content while crude fat has the lowest when amount of added Fe (II)-HPH in feed is 2 g/kg. The Fe content is significantly improved while amount of added is 1, 2, 4 g/kg. The Ca content is significantly improved and the Zn content is significantly improved while amount of added was 2 g/kg. Mn contents are significantly lower than control while amount of added is 4 g/kg. Based on analysis of amino acids in each group, the nutritional value of loach meat with 2 g/kg Fe (II)-HPH addition amount is relatively high, total amount of essential amino acids increases significantly, and EAA/TAA and EAA/NEAA improve significantly. In conclusion, adding 2 g/kg Fe (II)-HPH to feed could improve the nutritional values of loach meat
Assessment of the Effect of Cold Atmospheric Plasma (CAP) on the Hairtail (Trichiurus lepturus) Quality under Cold Storage Conditions
No full textCold Atmospheric Plasma (CAP) is a novel non-thermal preservation method that extends the shelf-life of food. Therefore, this study investigated the effect of CAP on the quality parameters of hairtail (Trichiurus lepturus) during cold storage conditions (at 4 °C and RH range 45–55%). For that reason, different quality parameters including the total bacteria count (TBC), total volatile basic nitrogen (TVB-N), pH, thiobarbituric acid reacting substances value (TBARS), color, texture, and sensory evaluation have been measured. The hairtail was exposed to CAP at 50 kV voltage for 2, 3, 4, and 5 min. The results showed that the samples treated with CAP at 50 kV for 5 min had significantly lower (p < 0.05) TBC (7.04 ± 0.26 log CFU/g) compared with the control sample (8.69 ± 0.06 log CFU/g). Similar results were found concerning TVB-N, which strongly decreased in the treated samples (16.63 ± 0.03 mg N/100 g) in comparison with the control sample (22.79 ± 0.03 mg N/100 g). In addition, the CAP-treated samples had lower (p < 0.05) changes in color than those of the control group. With reference to the sensory evaluation, the shelf-life of CAP-treated samples (at 50 kV for 5 min) was longer than the untreated samples by about 6 days. These results led us to the conclusion that CAP can effectively delay spoilage and deterioration, slow the rise in pH, and maintain the sensory attributes of hairtail during cold storage conditions
- …
