The formation and conversion of characteristic aroma profiles and key harmful substances in different high-temperature processing of hairtail (Trichiurus Haumela).

The balance regulation between characteristic aroma and hazards in high-temperature processed fish is a hot spot. This study was aimed to explore the interactive relationship between the nutritional value, microstructures, aroma, and harmful substances of hairtail under different frying methods including traditional frying (TF), air frying (AF), and vacuum frying (VF) via chemical pattern recognition. The results indicated that VF-prepared hairtail could form a crunchy mouthfeel and retain the highest content of protein (645.53 mg/g) and the lowest content of fat (242.03 mg/g). Vacuum frying reduced lipid oxidation in hairtail, resulting in the POV reaching 0.02 mg/g, significantly lower than that of TF (0.05 mg/g) and AF (0.21 mg/g), and TBARS reached 0.83 mg/g, significantly lower than that of AF (1.96 mg/g) (P < 0.05), respectively. Notable variations were observedin the aroma profileof hairtail preparedfrom different frying methods. Vacuum frying of hairtail resulted in higher levels of pyrazines and alcohols, whereas traditional frying and air frying were associated with the formation of aldehydes and ketones, respectively. Air frying was not a healthy way to cook hairtail which produced the highest concentration of harmful substances (up to 190.63 ng/g), significantly higher than VF (5.72 ng/g) and TF (52.78 ng/g) (P < 0.05), especially norharman (122.57 ng/g), significantly higher than VF (4.50 ng/g) and TF (32.63 ng/g) (P < 0.05). Norharman and acrylamide were the key harmful substances in hairtail treated with traditional frying. The vacuum frying method was an excellent alternative for deep-fried hairtail as a snack food with fewer harmful substances and a fine aroma, providing a theoretic guidance for preparing healthy hairtail food with high nutrition and superior sensory attraction.

Characterization of bamboo shoots dietary fiber modified by ball milling and its role in altering the physicochemical properties of shrimp surimi.

A simple but robust strategy of ball milling (20 Hz, 30 Hz for 30 s, 60 s, 120 s, 180 s) was utilized to modify bamboo shoots fiber (BSDF) in shrimp surimi. The water holding capacity, swelling capacity, and oil binding capacity of 30 Hz-60 s milled BSDF exhibited the highest values of 5.61 g/g, 3.13 mL/g, and 6.93 g/g, significantly higher (P < 0.05) than untreated one (3.65 g/g, 2.03 mL/g, 4.57 g/g). Ball-milled BSDF exhibited a small-sized structure with the relative crystallinity decreased from 40.44 % (control) to 11.12 % (30 Hz-180 s). The myosin thermal stability, gelation properties of surimi were significantly enhanced by incorporating 20 Hz-120 s and 30 Hz-60 s BSDF via promoting protein unfolding, covalent hydrophobic interactions, and hydrogen bonding. A matrix-reinforcing and water entrapping effect was observed, exhibiting reinforced networks with down-sized water tunnels. However, BSDF modified at 180 s contributed to over-aggregated networks with fractures and enlarged gaps. Appropriate ball-milled BSDF (20 Hz-120 s, and 30 Hz-60 s) resulted in a significant decrease in α-helix (P < 0.05), accompanied by an increase of ß-sheets and ß-turn. This work could bring some insights into the applications of modified BSDF and its roles in the gelation of surimi-based food.

Conformation-Activity Mechanism of Alcalase Hydrolysis for Reducing In Vitro Allergenicity of Instant Soy Milk Powder.

Effective reduction of the allergenicity of instant soy milk powder (ISMP) is practically valuable for expanding its applications. This study optimized the enzymolysis technology of ISMP using single-factor experiments and response surface methodology, combined serological analysis, cellular immunological models, bioinformatics tools, and multiple spectroscopy techniques to investigate the effects of alcalase hydrolysis on allergenicity, spatial conformation, and linear epitopes of ISMP. Under the optimal process, special IgE and IgG1 binding abilities and allergenic activity to induce cell degranulation of alcalase-hydrolyzed ISMP were reduced by (64.72 ± 1.76)%, (56.79 ± 3.72)%, and (73.3 ± 1.19)%, respectively (P < 0.05). Moreover, the spatial conformation of instant soy milk powder hydrolysates (ISMPH) changed, including decreased surface hydrophobicity, a weaker peak of amide II band, lower contents of α-helix and ß-sheet, and an enhanced content of random coil. Furthermore, the linear epitopes of major soy allergens, 9 from glycinin and 13 from ß-conglycinin, could be directionally disrupted by alcalase hydrolysis. Overall, the structure-activity mechanism of alcalase hydrolysis to reduce ISMP allergenicity in vitro was preliminarily clarified. It provided a new research direction for the breakthrough in the desensitization of ISMP and a theoretical basis for revealing the potential mechanism of alcalase enzymolysis to reduce the allergenicity of ISMP.

Dual Action of Reduced Allergenicity and Improved Memory of Instant Soybean Powder Hydrolysates.

Soy allergens are susceptible to inducing allergic reactions in infants and young animals, which have an impact on the effective daily utilization of proteins. In this study, we used Alcalase-hydrolyzed instant soybean powder (ISP) to clarify the sensitization changes of instant soybean powder hydrolysates (ISPH), and we explored the assisted memory-enhancing effects. BALB/c mice in the ISPH group showed significant improvement in the allergy symptoms, with their allergy symptom scores decreasing to (1.57 ± 0.53) and their specific serum IgE and IgG1 binding capacity decreasing by 28.00 and 25.73% (P < 0.05), which suppressed the mast cell degranulation rate. Meanwhile, the plasma HIS and IL-4 levels decreased by 12.59 and 25.32%, and the plasma INF-γ and IL- 10 levels increased by 30.64 and 27.79%, which obviously regulated the imbalance of Th1/Th2 cells and attenuated the tissue damage (P < 0.05). Furthermore, ISPH improved behavioral characteristics, increased cholinergic system activity, reduced neuronal cell damage or apoptosis, and increased the number of Nissl bodies to help improve memory in Kunming mice (P < 0.05). In general, alcalase-hydrolyzed ISP had the dual effects of reducing allergenicity and aiding in memory improvement.

Nutritional value of different parts from sea eel (Astroconger myriaster) determined by untargeted-lipidomic approach.

With the diversity of consumer demands for healthy food, stricter requirements have been put forward for the product quality of sea eel (Astroconger myriaster). From the common experience, remarkable differences could be observed between different parts of the sea eel. The textures, basic nutritional compositions, and lipid compositions from seven parts of sea eel were investigated to reach a comprehensive evaluation of the nutritional value. Sea eel was high-fat fish which contained 21.65% to 22.84% crude fat from part one to part seven. The seventh segment exhibited a lower moisture content (51.32%) and higher contents of protein (22.76%), ash (2.46%), carbohydrate (0.80%). The third and fourth parts remained higher hardness and good water-holding capacity. Sea eel had sixteen fatty acids, and the tail possessed a higher proportion of n - 3/n - 6 polyunsaturated fatty acids. Twenty-seven lipid species were determined in sea eel, and highly unsaturated fatty acids mainly stemmed from triglycerides, while saturated fatty acids mainly existed as diglycerides. Section six and seven were primarily diglycerides and monoglycerides. According to the characteristics of different parts, it can provide support for standardized segmentation of sea eel and quality control of different parts.

Progress in the application of novel cryoprotectants for the stabilization of myofibrillar proteins.

In this review, the physicochemical and conformational changes of myofibrillar proteins (MPs) of freeze-induced mince-based aquatic foods were comprehensively summarized in depth. Studies have demonstrated that temperature fluctuation and long-time freezing negatively affect food quality, resulting in texture alteration, drip fluid, flavor degradation, and nutrition loss due to MPs denaturation, aggregation, and oxidation. Attempts have been made in ice-recrystallization inhibition, freezing point depression, and ice shape and growth control for better cryopreservation. Moreover, to further minimize the quality deterioration, cryoprotectants were acknowledged to reduce the denaturation and aggregation of the MPs effectively. Recently, interest in novel functional ingredients, including oligosaccharides, protein hydrolysates, and natural polyphenols demonstrated excellent cryoprotective effects while avoiding health concerns and undesirable flavor caused by traditional sugar-based or phosphates-based cryoprotectants. Therefore, the present review provides a systematic overview of these low molecular weight multifunctional substances with a particular sequence and highlights their underlying mechanism in the inhibition of ice recrystallization the stabilization of MPs.

Effects of partial replacement of unwashed Antarctic krill surimi by Litopenaeus vannamei surimi on the heat-induced gelling and three-dimensional-printing properties.

There is an emerging consumption of the Antarctic krill (AK) muscle-based food due to its excellent nutritional value and enormous biomass storage capacity. However, the coarse texture of the muscle and the weak gelling properties of AK protein impede its expansion in surimi-based products. This investigation successfully prepared heat-induced gels of AK surimi with desirable textural properties by including Litopenaeus vannamei in varying proportions. Higher concentrations of L. vannamei resulted in improved three-dimensional printability, greater water-holding capacity (WHC), larger viscoelastic modulus, and a well-formed microstructural matrix of AK surimi, due to an increased level of myofibrillar protein. Compared with AK, L. vannamei muscle had double the salt-soluble protein content, which was corroborated by increased intensity of bands of actin, paramyosin, tropomyosin, and myosin light chains on reducing SDS-PAGE. DSC results indicated that a high ratio of L. vannamei elevated the denaturation temperature and enthalpy of myosin, sarcoplasmic protein, and actin, suggesting a high degree of cross-linking. It was also found that when hydroxypropyl cassava starch was added at 0.5% (w/w), WHC and gel strength were further improved with a more compact gel matrix. The successful preparation of unwashed mixed surimi with AK meat fully exploited in this study provides an option for AK surimi-based product industrialization.

Marine Bioactive Compounds as Nutraceutical and Functional Food Ingredients for Potential Oral Health.

Oral diseases have received considerable attention worldwide as one of the major global public health problems. The development of oral diseases is influenced by socioeconomic, physiological, traumatic, biological, dietary and hygienic practices factors. Currently, the main prevention strategy for oral diseases is to inhibit the growth of biofilm-producing plaque bacteria. Tooth brushing is the most common method of cleaning plaque, aided by mouthwash and sugar-free chewing gum in the daily routine. As the global nutraceutical market grows, marine bioactive compounds are becoming increasingly popular among consumers for their antibacterial, anti-inflammatory and antitumor properties. However, to date, few systematic summaries and studies on the application of marine bioactive compounds in oral health exist. This review provides a comprehensive overview of different marine-sourced bioactive compounds and their health benefits in dental caries, gingivitis, periodontitis, halitosis, oral cancer, and their potential use as functional food ingredients for oral health. In addition, limitations and challenges of the application of these active ingredients are discussed and some observations on current work and future trends are presented in the conclusion section.

Reducing the allergenicity of pea protein based on the enzyme action of alcalase.

Enzymatic hydrolysis could be one of the crucial means to limit the allergenicity of allergens. The allergenicity of pea peptides was evaluated using indirect ELISA and RBL-2H3 cell assay, thereby obtaining hypoallergenic pea peptide sequences. Results indicated that pea protein-sensitized mice produced higher levels of total IgG1 and IgE antibodies than the mice in the control group (P < 0.05). Moreover, the allergenicity of hydrolysates decreased significantly after enzymolysis, and the allergenicity of ultrafiltration component F1 and purified component F1-2 was significantly lower than that of other isolated and purified components (P < 0.05). Furthermore, ADLYNPR identified from F1-2 had lower binding capacity to specific IgE and IgG1 and lower degree of cell degranulation with a higher EC50 value of 6.63 ng mL-1, which was about 36.83 times that of pea protein (P < 0.05). Based on the above results, ADLYNPR might be a potential source of hypoallergenic peptides.

Formation and conversion of characteristic volatile compounds in grilled eel (Astroconger myriaster) during different processing steps.

The aroma of grilled eel is affected by three key processing steps: curing, steaming, and grilling. This study was aimed at the determination of the difference between the characteristic volatiles in each processing stage and their influence on the final aroma of grilled eel. A total of 92 volatile compounds were identified by purge and trap (P&T) combined with gas chromatography-mass spectrometry (GC-MS) throughout the processing. Alcohol, ketone, aromatic compounds and methylated compounds were the most important volatiles in the eel meat during processing. Pyrazine was generated gradually during the entire process, and 2,3-dimethylpyrazine was only found in the sample after grilling. Distinct odors among the raw and treated samples could be indirectly distinguished according to their volatile compounds, analyzed by heatmap. Together, these results indicate a relationship between the final aroma and the whole processing. The odor coding made from the odor activity value (OAV) could be as a reference benchmark for the grilled eel product.

Flavor formation in different production steps during the processing of cold-smoked Spanish mackerel.

This study aimed to determine the changes in the flavor profile during different operating units when making cold-smoked Spanish mackerel. Sensory evaluation and instrumental analysis of tenderness were applied to optimize the processing parameters. For the overall odor perception, distinct odor among fresh and processed samples could be distinguished using electronic nose (e-Nose). Purge-and-trap (P&T) extraction combined with gas chromatography-mass spectrometry (GC-MS) was used to identify volatile compounds. Alcohols were the major volatiles in Spanish mackerel over the whole processing, while 2-butanol was found in the highest concentration. Curing was an effective way to remove fishy odor. Drying decreased the concentration of volatiles, especially sulfur compounds. Odor formation in cold-smoked mackerel could be divided into four steps (curing, drying, cold smoking and heating) as a result of partial least squares discriminant analysis (PLS-DA).

Preparation of the rainbow trout bone peptides directed by nutritional properties and flavor analyses.

Rainbow trout bone proteins were prepared by heating at 121°C for 30 min, followed by filtration, concentration, and lyophilization. Nutritional properties and flavor analyses of hydrolysates digested by five different enzymes were investigated, respectively. Results showed that the crude protein content of rainbow trout bone was 15.90% and had a well-balanced nutritional value. The content of total amino acids was 983.64 mg/g. The amount of free amino acids of hydrolysates digested by alkaline protease, neutral protease, flavourzyme, papain, and trypsin for 3 hr was 207.83, 224.13, 1,001.59, 283.26, and 303.64 mg/g, respectively. During the hydrolysis, the main flavor compounds were identified by GC-MS to be alcohols, aldehydes, ketones, acids, and alkanes. After hydrolysis, the main molecular weight of peptides was focused on the range of 1,000-3,000 Da in all enzymatic hydrolysates. This study provided a theoretical basis to comprehensive utilization of rainbow trout bone in food industry.

Analysis of volatile compounds and nutritional properties of enzymatic hydrolysate of protein from cod bone.

Hydrolysis of the proteins from cod bone was performed using flavourzyme and trypsin. The nutritional properties of hydrolysates by flavourzyme (HF) and trypsin (HT) were investigated. By comparison, HF exhibits a better degree of hydrolysates (DH) and nitrogen recovery (NR) than HT. The protein content of extract is 97.39% and had a good nutritional value due to the high protein digestibility-corrected amino acid score (PDCAAS) of 0.95 for adults. The content of total amino acids is 942.55 mg/g. The free amino acids content of hydrolysates derived from flavourzyme is 136.82 mg/g after hydrolyzing 3 h, while 17.12 mg/g of such hydrolysates was obtained by using trypsin. The main flavor compounds are alcohols, aldehydes, ketones, acids and alkanes. The molecular weight of predominant peptides ranged from 1000 to 3000 Da in both enzymatic hydrolysates. This study provided a theoretical basis to the preparation of nutritional components with attracting flavor in functional food industry.