The nutritional components of different parts (meat, head, shell and tail) of Litopenaeus vannamei (L.v), Macrobrachium rosenbergii (M.r), Penaeus monodon (P.m), Fenneropenaeus chinensis (F.c), and Penaeus japonicus (P.j) were analyzed and their nutritional values were evaluated. For the five species of shrimp, the meat yield was 37.47–55.94%, and the byproduct yield was 44.06–62.53%. The meat yields of L.v and F.c were the highest (55.94 and 55.92%, respectively), and the meat yield of M.r was the lowest (37.47%). The shrimp contain high amounts of crude protein, and the values of the amino acid score (AAS), chemical score (CS), and essential amino index (EAAI) were greater than or close to 1.00, indicating that shrimp protein had higher nutritional value. The shrimp head was rich in polyunsaturated fatty acids and the ratio of n-6 to n-3 PUFAs was from 0.37 to 1.68, indicating that the shrimp head is rich in n-3 PUFAs and is a good source of n-3 PUFAs. The five species of shrimp were rich in macro- and micro-minerals, especially in shrimp byproducts. The shrimp byproducts were also rich in other bioactive ingredients (astaxanthin), which are also very valuable for developing biological resources. Therefore, shrimp have many nutritional benefits, and their byproducts can also be used to develop natural nutraceuticals, which are considered to be one of the healthiest foods.

Litopenaeus vannamei is one of the most popular shrimp species in the world and has been reported in studies on its dryness and flavor. However, the aroma characteristics of shrimps dried with different drying methods are compared in a unified way, and there are few reports on the difference in aroma of different shrimps dried. In order to clarify the difference in aroma characteristics of shrimp dried produced by different drying methods. In this study, blanched shrimp (BS) was used as a control to analyze the aroma characteristics of shrimp dried by five different procedures (SD-BFDP) samples, namely vacuum freeze-dried shrimp (VFDS), vacuum dried-shrimp (VDS), heat pump-dried shrimp (HPDS), hot air dried-shrimp (HADS) and microwave vacuum-dried shrimp (MVDS). An electronic nose (E-nose) was used to obtain the aroma fingerprint of SD-BFDP samples. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used for qualitative and quantitative analysis of volatile compounds in SD-BFDP samples. Partial least squares regression (PLSR) was used to analyze potential correlations between sensory attributes and aroma-active compounds (AACs). Partial least squares-discrimination analysis (PLS-DA) was used to screen for signature aroma compounds. The results of the E-nose showed that there were differences in the aroma fingerprints of the SD-BFDP samples, and the E-nose could distinguish the five kinds of SD-BFDP. The qualitative and quantitative results of GC-MS showed that the types and contents of the main volatile components of SD-BFDP samples were different. 15 AACs were screened from SD-BFDP based on odor activity value (OAV). The PLSR results showed good correlations between certain sensory attributes and the majority of AACs. PLS-DA results displayed that aroma attributes of SD-BFDP samples could be distinguished by six signature aroma compounds, including trimethylamine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, nonanal, 3-ethyl-2,5-dimethylpyrazine, and octanal. These research results reveal that shrimps dried in different procedures have unique aroma characteristics, which could provide a theoretical basis for the rapid identification of aroma attributes of dried shrimps in the future. From a flavor perspective, MVD is the best drying method.

Antarctic krill is a high-quality animal protein resource, but the presence of fluorine limits its development. Antarctic krill defluoridated hydrolysate products (DHPs) generally have a bitter taste that is unacceptable to consumers. Therefore, it is necessary to improve the flavor of defluoridated hydrolysate. In this work, flavor improvement of DHPs by the Maillard reaction was evaluated by sensory analysis, electronic nose (E-nose), and gas chromatography-mass spectrometry (GC-MS). The potential correlations among the signals of sensory attributes, E-nose, and volatile components were analyzed using the analysis of partial least squares regression (PLSR). A total of 63 volatile compounds were identified and quantified via GC-MS. The flavors in Maillard reaction products were mainly attributed to pyrazines, aldehydes, ketones, and furans. After the Maillard reaction, the two main aromatic compounds generated were 3-ethyl-2,5-dimethylpyrazin (roast odor, OAV = 32.7) and 3-(methylthio) propionaldehyde (shrimp meat odor, OAV = 16.43), which contributed to flavor improvement in DHPs. PLSR results showed a good correlation between most variables of sensory attributes, E-nose, and volatile compounds, which indicates that the overall flavor of DHPs was improved by the Maillard reaction. Abbreviations: DHPs: defluoridated hydrolysate products; MRPs: Maillard reaction products; GC-MS: gas chromatography-mass spectrometry; E-nose: electronic nose; OAV: odor activity value; SPME: solid-phase microextraction; GC-O: gas chromatography-olfactometry; PCA: principal component analysis; PLSR: partial least squares regression

Salmonella enterica serovar Typhimurium (ST) is a predominant serovar causing foodborne illnesses worldwide. Traditional detection methods often face challenges, including the need for specialized equipment, skilled operators, and lengthy procedures. To address these limitations, we developed a rapid, sensitive, and specific ST detection method by integrating loop-mediated isothermal amplification (LAMP) with the clustered regularly interspaced short palindromic repeats and associated protein 12b (CRISPR/Cas12b) system, all within a single tube. Our results indicate that the LAMP–CRISPR/Cas12b reaction can be completed isothermally in under 1 h without requiring specialized instruments. The platform’s limit of detection (LoD) is 12.5 copies per reaction. Additionally, the system demonstrated 100% inclusivity and exclusivity when tested against 30 reference strains, highlighting its specificity. In practical applications, the LoDs for ST in pure nucleic acid and contaminated fecal samples were 2.32 and 23.2 CFU/mL, respectively, with higher sensitivity observed in pure nucleic acid samples. Overall, our findings underscore the potential of the one-tube LAMP–CRISPR/Cas12b platform as a rapid, sensitive, and specific tool for ST detection, particularly in resource-limited settings. IMPORTANCE: Here, we have provided a novel one-step method for Salmonella Typhimurium detection in one pot by integrating the LAMP assay with the CRISPR/Cas12b system, offering significant advantages in terms of simplicity, speed, and accuracy.

In the present paper, the role of amino acids of Penaeus vannamei was investigated in the formation of volatile substances during drying. The variations in volatile substances among samples with different moisture contents (raw, 45%, 30%, 15%, and 5%) were obtained by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS). The amino acid contents of the above samples were measured by the amino acid automatic analyzer. Correlation between pyrazines and the various amino acid contents was analyzed by the Pearson correlation coefficient. Their correlation was verified by conducting addition assays. The types and contents of volatile components increased significantly in samples with moisture contents between 30% and 5%. The most obvious increases in the type, content and odor activity value of pyrazines were observed in this range. Basic amino acids (Arg, Lys, and His) had a strong correlation with the formation of pyrazines. Addition assays verified that the addition of Arg and Lys increased the content of pyrazines in shrimp after drying.