Real-Time Monitoring of the Quality Changes in Shrimp (Penaeus vannamei) with Hyperspectral Imaging Technology during Hot Air Drying

Dietary Phaffia rhodozyma-Synthesized 3S, 3'S-Astaxanthin Promotes Body Coloration and Muscle Quality in Pacific White Shrimp Litopenaeus vannamei

The focus of people on the yield of aquatic products has gradually shifted to superior quality. Astaxanthin is well-known for its superior antioxidant capacity, while research on its regulatory effect on muscle quality is limited. This study aims to investigate whether dietary Phaffia rhodozyma-synthesized 3S, 3'S-astaxanthin (L-AST) could promote the body coloration and muscle quality of Litopenaeus vannamei. Experimental diets with L-AST levels of 0, 30, 60, and 90 mg/kg were fed to L. vannamei (IBW: 2.72 ± 0.03 g) for 8 weeks. The results revealed that the shrimp fed L-AST diets presented better body coloration with decreased L ∗ values whereas increased a∗ values and possessed higher levels of muscle astaxanthin. Dietary supplementation with 60 mg/kg L-AST significantly enhanced muscle texture (hardness, chewiness, resilience, and gumminess), which could be attributed to an increase in alkaline-insoluble collagen content and a decrease in myofiber diameter. Interestingly, dietary supplementation with 60 or 90 mg/kg L-AST markedly increased the content of glycine (a sweet amino acid) and total flavor amino acid (glutamic acid, aspartate, alanine, glycine). Further study showed that dietary supplementation with 60 or 90 mg/kg L-AST significantly improved free fatty acid profile by increasing contents of some monounsaturated fatty acids (C17:1n7, C18:1n9t and C24:1n9) and polyunsaturated fatty acids (C20:02 and C22:6n3). Taken together, dietary P. rhodozyma-synthesized L-AST considerably promoted muscle quality in L. vannamei by promoting histological and texture properties, elevating alkaline-insoluble collagen content while improving the profile of free amino acids and fatty acids.

Heat and Mass Transfer in Shrimp Hot-Air Drying: Experimental Evaluation and Numerical Simulation

Shrimp is one of the most popular and widely consumed seafood products worldwide. It is highly perishable due to its high moisture content. Thus, dehydration is commonly used to extend its shelf life, mostly via air drying, leading to a temperature increase, moisture removal, and matrix shrinkage. In this study, a mathematical model was developed to describe the changes in moisture and temperature distribution in shrimp during hot-air drying. The model considered the heat and mass transfer in an irregular-shaped computational domain and was solved using the finite element method. Convective heat and mass transfer coefficients (57.0-62.9 W/m2∙K and 0.007-0.008 m/s, respectively) and the moisture effective diffusion coefficient (6.5 × 10-10-8.5 × 10-10 m2/s) were determined experimentally and numerically. The shrimp temperature and moisture numerical solution were validated using a cabinet dryer with a forced air circulation at 60 and 70 °C. The model predictions demonstrated close agreement with the experimental data (R2≥ 0.95 for all conditions) and revealed three distinct drying stages: initial warming up, constant drying rate, and falling drying rate at the end. Initially, the shrimp temperature increased from 25 °C to around 46 °C and 53 °C for the process at 60 °C and 70 °C. Thus, it presented a constant drying rate, around 0.04 kg/kg min at 60 °C and 0.05 kg/kg min at 70 °C. During this stage, the process is controlled by the heat transferred from the surroundings. Subsequently, the internal resistance to mass transfer becomes the dominant factor, leading to a decrease in the drying rate and an increase in temperatures. A numerical analysis indicated that considering the irregular shape of the shrimp provides more realistic moisture and temperature profiles compared to the simplified finite cylinder geometry. Furthermore, a sensitivity analysis was performed using the validated model to assess the impact of the mass and heat transfer parameters and relative humidity inside the cavity on the drying process. The proposed model accurately described the drying, allowing the further evaluation of the quality and safety aspects and optimizing the process.

Comparison of non-volatile compounds of Penaeus vannemei with different drying treatments via multidimensional infrared spectroscopy

To analyze the effect of various drying treatments (microwave drying (MD), hot air drying (HAD), vacuum drying (VD), and vacuum freeze drying (VFD)) on taste compounds in Penaeus vannamei, relevant indicators such as free amino acids, 5'-nucleotides, and organic acids were performed. Multidimensional infrared spectroscopy (MM-IR) results found that there were notable variations in taste properties of P. vannamei. There were 18 autocorrelation peaks in 3400-900 cm-1 were screened using second-derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR). Variations in functional groups were the major contributors to taste profiles. The TAV of glutamic acid (Glu), guanine (GMP), and inosinemonphosphate (IMP) were greater than one and had notable impacts on taste profiles. VD had the highest equivalent umami value, followed by VFD, HAD, and MD. This study may provide a theoretical guide for the production of dried P. vannamei products on an industrial scale.

A two-dimensional correlation spectroscopy analysis-based approach for asymptomatic rot detection in stored potatoes using hyperspectral imaging

Fusarium dry rot (FDR), which is caused by several Fusarium species, is a major disease affecting potatoes during storage. The study aimed to identify the gleyic stage and monitor rot progression in stored potatoes using a hyperspectral imaging (HSI) system. We evaluated the susceptibility parameters and quality attributes during the infection process and monitored starch, soluble protein, malondialdehyde, and aerobic bacterial contents in all samples. To further characterize the infection process, we collected spectral data on different storage days and then mapped these data using two-dimensional correlation spectroscopy. The results revealed 20 peaks related to these component contents. Then, the quantitative analysis models of these indicators were established based on the 2D correlation synchronization spectrum. The optimal correlation coefficients of the validation set were 0.9273, 0.9634, 0.9470, and 0.9487 for these indicators. Visual analysis was implemented to these indicators, and the content distribution can be effectively observed on hyperspectral images.

Uncovering quality changes of shrimp (Penaeus vannamei) during solar drying and its relationship with protein-related properties

This study explored the intrinsic relationship between the quality traits and protein-related property changes during the solar drying of shrimps (Penaeus vannamei). During drying, the shrimp exhibited a gradual decline in L*a*b* values and a notable increase in the hardness and chewiness. Proteins were degraded and oxidized. Especially, the trichloroacetic acid-soluble peptide and carbonyl contents increased, whereas the total sulfhydryl content decreased. The proportions of different types of intramolecular bonds were significantly changed. The ionic and hydrogen bonds greatly decreased to 10.72% and 9.05% and the hydrophobic and disulfide bonds notably increased to 19.38% and 28.19%, indicating the changes in the spatial structure of the protein and its denaturation during the drying process. The Pearson's correlation analysis showed that protein degradation and denaturation greatly affected the textural properties and protein oxidation caused color changes. The result of this work provides a theoretical support for improving the quality of shrimp products.

Evaluation of aroma characteristics of Penaeus vannamei with different drying methods using HS-SPME-GC-MS, MMSE-GC-MS, and sensory evaluation

The effects of microwave drying (MD), hot air drying (HAD), vacuum hot air drying (VD), and vacuum freeze drying (VFD) on the volatile profiles of Penaeus vannamei were investigated. A total of 89 and 94 volatile compounds were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and monolithic material sorptive extraction gas chromatography-mass spectrometry (MMSE-GC-MS), respectively. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable influence on projection (VIP) models were utilized to select characteristic volatiles and key marker compounds (e.g., octanal, 1-octen-3-ol, 2-methyl-butanal, 2-ethyl-furan, and trimethyl-pyrazine) to discriminate among four drying methods. Based on synthesis of odor descriptions and sensory evaluation, it was found that P. vannamei via MD, HAD, and VD greatly reduced the fishy and generated roasted, fatty, and smoked odors. This study systematically analyzed the aroma characteristics of four traditional dried P. vannamei products, which may provide theoretical guidance for industrial production.

Polystyrene nanoplastics exposure alters muscle amino acid composition and nutritional quality of Pacific whiteleg shrimp (Litopenaeus vannamei)

Litopenaeus vannamei were exposed to 80-nm polystyrene nanoplastics (NPs) at different concentrations (0, 0.1, 1, 5, and 10 mg/L) for 28 days to study the effects on muscle nutritional quality. Our results showed that with increasing NPs concentrations, the survival rate, specific gain rate, and protein efficiency ratio decreased but the feed conversion ratio increased. There was no significant difference in moisture, ash, and crude lipid content in the muscle, and a general decrease in crude protein content was observed. However, the total amino acid and semi-essential amino acid contents decreased. The spacing between muscle fibers and the melting morphology of muscle increased. The hardness of muscle flesh texture increased, but springiness, cohesiveness, and chewiness decreased. Regarding antioxidant enzyme activity, the activity of catalase decreased, but the total antioxidant capacity, superoxide dismutase activity, and reduced glutathione first increased and then decreased. The expression level of the growth-related genes retinoid X receptor (RXR), chitin synthase (CHS), and calmodulin A (CaM) first increased then decreased, but calcium/calmodulin-dependent protein kinase I (CaMKI), ecdysteroid receptor (EcR), chitinase 5 (CHT5), cell division cycle 2 (Cdc2), and cyclin-dependent kinase 2 (CDK2) decreased. Our results suggest that exposure to NPs can inhibit growth by inducing oxidative stress, which leads to muscle tissue damage and changes in amino acid composition. These results will provide a theoretical reference for the risk assessment of NPs and the ecological health aquaculture of shrimp.

Fast Nondestructive Detection Technology and Equipment for Food Quality and Safety

Fast nondestructive detection technology in food quality and safety evaluation is a powerful support tool that fosters informatization and intelligence in the food industry, characterized by its rapid processing, convenient operation, and seamless online inspection [...].