红萝卜快速发酵工艺的研究

实验是以红萝卜为原料,添加植物乳杆菌发酵生产酸味萝卜丝.以发酵液pH值和萝卜丝感官评价为指标,通过单因素和正交试验确定了植物乳杆菌发酵生产酸味萝卜丝和保脆工艺条件.实验结果表明,酸味萝卜丝生产工艺条件为:盐浓度6％,温度30℃,植物乳杆菌接种量为7％.发酵周期仅为72 h;保脆剂CaCl2的添加量为0.1％.     

Relationship between lysyl oxidase activity,pyridinoline content and muscle texture during ice storage of jumbo squid (Dosidicus gigas)

Collagen fibres, stabilised by lysyl oxidase (LOX), play an important role in jumbo squid because they are responsible for the union between various cells; therefore, a close interdependence between their functions and muscle firmness during ice storage has been suggested. In this study, the relationship between LOX activity, pyridinoline (Pyr) content and muscle texture (SF) during ice storage of jumbo squid mantle was evaluated. LOX activity was confirmed within the range of 4.1–7.1 × 10^?3 U g^?1 of protein, leading to an increase in Pyr content, detected in the range of 0.85–1.32 mmol mol^?1 of collagen after 5–20 days. The SF of the muscle became harder during the ice storage time, increasing from 21.08 to 37.95 N. It was therefore possible to establish the relationship between LOX activity, collagen cross‐links (Pyr content) and texture patterns during ice storage of jumbo squid muscle, which increased after 20 days.     

小包装鱿鱼丝精确称量工艺的研究

通过研究发现,在鱿鱼丝称量前,控制其拉丝细度,并对原料预先进行整理、疏散都能有效的提高称量精确率.采用定量初称+二次复秤补偿的方法能更进一步提高称量精度.通过正交实验,结果表明:称量小包装化鱿鱼丝时,堆料密度为0.75 g/cm2,物料均重介于1g与1.5 g之间,补偿量为10%,在此工艺条件下,所获得的称量精确率最高...     

Isolation and properties of 5′-nucleotidase isolated from jumbo squid (Dosidicus gigas) mantle muscle from the Gulf of California,Mexico

The enzyme 5′-nucleotidase of jumbo squid (Dosidicus gigas) mantle was purified and its SDS–PAGE showed a single band of 33 kDa, whereas a protein with a molecular mass of 107 kDa was detected by gel filtration suggesting a homotrimeric nature of this enzyme. Subunits of the named enzyme were not linked by covalent bonds. Isoelectric focusing of this enzyme showed a pI of 3.6–3.8 and presented a hyperbolic kinetics with V_max of 1.16 μM/min/mg of protein, K_m of 1.49 mM, K_cat of 3.48 μM of P_ι s⁻¹ and K_cat/K_m relation of 356.52 ((mol/L)⁻¹ s⁻¹). Purified enzyme preferred AMP as substrate (by 6.7-folds) than IMP, showing a K_m of 6.34 mM, V_max of 0.19 μM/min/mg of protein a K_cat of 0.3388 mol of P_ι s⁻¹ and K_cat/K_m relation of 53.44 ((mol/L)⁻¹ s⁻¹). The low K_m in relation to purified AMP deaminase of the same organism suggested a high contribution of 5′-nucleotidase in AMP degradation in jumbo squid mantle.     

Computational Study on a Squid-Like Underwater Robot with Two Undulating Side Fins

The undulating fin propulsion system is an instance of the bio-inspired propulsion systems. In the current study, the swimming motion of a squid-like robot with two undulating side fins, mimicking those of a Stingray or a Cuttlefish, was investigated through flow computation around the body. We used the finite analytic method for space discretization and Euler implicit scheme for time discretization along with the PISO algorithm for velocity pressure coupling. A body-fitted moving grid was generated using the Poisson equation at each time step. Based on the computed results, we discussed the features of the flow field and hydrodynamic forces acting on the body and fin. A simple relationship among the fin's principal dimensions was established. Numerical computation was done for various aspect ratios, fin angles and frequencies in order to validate the proposed relationship among principal dimensions. Subsequently, the relationship was examined base on the distribution of pressure difference between upper and lower surfaces and the distribution of the thrust force. In efficiency calculations, the undulating fins showed promising results. Finally, for the fin, the open characteristics from computed data showed satisfactory conformity with the experimental results.     

Weighted cluster in mobile ad hoc network using enhanced long short-term memory-based squid game optimizer concept

A collection of autonomous frameworks will most likely make up a wireless mobile network. They are not solely dependent on a wireless network with no established infrastructure. In the mobile ad hoc network, it is highly challenging to safeguard the viability of the cluster head (CH) within a cluster; therefore, this research provides a big scope for routing utilizing enhanced long short-term memory–squid game optimizer (ELSTM-SGO). The quality of service attribute of the nodes determines which CH is chosen within them. How long the CH will hold will depend on the weight applied to it. The best CH is chosen using an ELSTM-SGO routing method within a cluster, and the best CH will improve the routing. The three procedures that make up the developed ELSTM-SGO protocol are SGO, CH selection, and cluster's gateway. The wireless system's energy consumption, buffer size, packet delivery ratio, routing overhead and end-to-end delay throughput represent the characteristics used in the suggested approach. Weighted clustering approach is evaluated on the system. According to the results of the experimental research, ELSTM-SGO yields superior results for preserving the resiliency of the CH.     

鱿鱼酶解鲜味汁Cd2+脱除工艺研究

以鱿鱼酶解鲜味汁为研究对象,利用碳羟基磷灰石（CHAP）脱除其中的重金属Cd2+,以脱镉率作为衡量该工艺的指标。分别研究了CHAP的用量、pH、温度3个单因素对脱除的影响,并在此基础上应用中心组合设计（CCD）原理和响应面分析法（RSM）,研究各个变量及其交互作用对脱除率的影响,同时模拟构建了三元二次回归方程的预测模型。结果表明,在固液比为1∶0.5（w/v）的条件下,脱除重金属Cd2+的最佳工艺参数为:CHAP用量32.5g/L、pH取5.4、温度为50.0℃。在该工艺参数下,鲜味汁中的重金属Cd2+脱除率达93.1%,使产品重金属Cd2+含量符合食品安全的限量标准。      

响应面法优化鱿鱼缠卵腺糖蛋白提取工艺研究

以鱿鱼缠卵腺为原料,在单因素实验的基础上,通过响应面实验设计优化了鱿鱼缠卵腺糖蛋白提取的工艺条件。结果表明,从鱿鱼缠卵腺中提取糖蛋白的最佳工艺条件为:提取时间3.5h,提取温度25℃,NaOH浓度0.37mol/L,在该条件下,提取率为12.79%,获得的糖蛋白中糖含量为72.5%,蛋白含量22.7%,硫酸根含量3.0%,是一种硫酸化的粘蛋白。      

Bioactive peptides from collagen hydrolysates from squid (Dosidicus gigas) by-products fractionated by ultrafiltration

The bioactive properties of peptide fractions obtained from the hydrolysis of squid (Dosidicus gigas) by-products collagen, using Protease type XIV and ultrafiltration (UFI), were studied. The basic objective was to improve the bioactivity of squid hydrolysates via the application of UFI. Peptide fractions obtained after UFI had higher antioxidant and antimutagenic activities, but the antiproliferative activity did not improve after UFI. Peptides <5 kDa (Fraction F3) showed higher antioxidant and antimutagenic activities, as well as lower antioxidant and antiproliferative activities than both, peptides >10 kDa (F1) and those within the range of >5 to <10 kDa (F2). Band at lower field observed in FT-IR spectra and proton-peaks observed at higher ¹H-NMR fields, both associated to aromatic amino acids, as well as to other antioxidant amino acids such as hydroxyproline, glycine, arginine and lysine, may explain F3 bioactivity. Ultrafiltration can, therefore, be used to improve some bioactivities of squid collagen hydrolysates.