Intake of essential and non-essential elements from consumption of octopus,cuttlefish and squid

Total concentrations of essential (Cu, Zn, Se and Cr) and non-essential (Hg, Cd, Pb and As) trace elements were measured in the flesh and hepatopancreas of Octopodidae (Eledone moschata, Eledone cirrhosa, Octopus salutii), Sepiidae (Sepia elegans, Sepia orbignyana) and Loliginidae (Illex coindeti, Loligo vulgaris) from the Mediterranean Sea. As expected, the hepatopancreas showed higher metal concentrations than flesh; the only exceptions were Hg and As, which were equally distributed in the two tissues. Regarding the edible portion, the highest toxic metal concentrations were in Octopodidae (Hg: 0.44, Cd: 0.49, Pb: 0.10 µg g^?1 wet weight) and Sepiidae (Hg: 0.27, Cd: 0.50, Pb: 0.12 µg g^?1 wet weight), while Loliginidae tended to accumulate less metal, especially Hg (Hg: 0.11, Cd: 0.30, Pb: 0.05 µg g^?1 wet weight). The other elements showed a heterogeneous distribution among the different cephalopod families. Loliginidae showed the highest Se concentrations (1.18 µg g^?1 wet weight), Octopodidae of Cu (37.37 µg g^?1 wet weight) and Zn (42.00 µg g^?1 wet weight) and Sepiidae of As (61.43 µg g^?1 wet weight), while Cr was uniformly distributed among the various families (0.38–0.43 µg g^?1 wet weight). In these seafoods, the concentrations of essential and non-essential elements were within the prescribed limits set by various authorities, except for Cu and As. Health risks posed by toxic elements to humans via dietary intake of these mollusks were assessed on the basis on Provisional Tolerable Weekly Intake (PTWI), while the estimated intakes of essential elements were compared to Dietary Reference Intakes (RDIs). A 70-g serving of these mollusks was shown to provide a large contribution to Cd intake (0.89 µg kg^?1 body weight), corresponding to 35.6% of PTWI. Concerning the essential elements, the consumption of these mollusks made an important contribution to daily dietary intake of Se, Cu and Zn.     

Surveillance of cadmium level in octopus, squid, clam, short-necked clam and chocolate

In order to investigate cadmium contents in foods sold in Japan, cadmium levels in 40 seafood samples and 30 chocolate samples were measured by means of atomic absorption spectrometry and ICP-OES. We first confirmed the validity of the method according to the guidelines of the Ministry of Health, Labour and Welfare. Among 40 seafood samples investigated, cadmium was detected in 31 samples, in which the concentration exceeded half the LOQ (0.025 mg/kg), and the level was ranged from 0.03 to 0.38 mg/kg. We could not find any sample containing cadmium in excess of 2 mg/kg, which the Codex Alimentarius sets as the maximum standard value. Among 30 chocolate samples, cadmium was detected in 21 samples, and the level ranged from 0.025 to 0.54 mg/kg.     

Concentrations of biogenic amines in fish,squid and octopus and their changes during storage

The concentrations of seven biogenic amines (BA) were simultaneously determined in 74 samples of fish, squid and octopus, by the method of HPLC coupled with pre-column derivatisation. The relationship between the formation of BA in aquatic products and the growth of microbial flora during storage was also investigated. Results showed that putrescine, cadaverine, histamine and tyramine were the dominant BA in the studied samples, but the concentrations of histamine and tyramine were mostly less than 50 and 100 mg kg⁻¹, respectively. Freezing can effectively prevent the formation of BA, but the levels of putrescine, cadaverine, histamine and tyramine significantly increased (p < 0.05) during storage at 4 and 25 °C. The growth of mesophilic or psychrophilic bacteria in blue scad and octopus strongly and positively correlated with the formation of amines (such as putrescine, cadaverine, histamine and tyramine) during storage, except for histamine in octopus.     

Intramuscular composition and texture of beef muscles

Total collagen, heat soluble collagen, fat, moisture, sarcomere length and pH were determined on 18 muscles from two commercial beef animals. Each muscle was given a mild, moderate or severe cooking and the toughness determined using a mechanical compressive test. From the force-deformation curve, measured throughout the test, three toughness values: the yield force, the final compressive force and the work done, were taken. In general, collagen content was associated with the compressive force and the other components with the yield force, although no precise distinction could be made. Collagen content, in particular the amount of total collagen, was the best predictor of toughness, but as the cooking became more severe, collagen accounted for progressively less of the variability in toughness. The other components contributed substantially to the variability in toughness only when meat was moderately cooked.     

Species authentication of octopus,cuttlefish, bobtail and bottle squids (families Octopodidae,Sepiidae and Sepiolidae) by FINS methodology in seafoods

In the present work a molecular a method for the authentication of cephalopods products was developed, which allows the genetic identification of about 30 species belonging to the families Octopodidae, Sepiidae and Sepiolidae. This molecular system is based on the phylogenetic analysis of DNA sequences. The molecular marker studied was the cytochrome b gene (cyt b), that was amplified by PCR and subsequently sequenced. The developed methodology was validated and further applied to 20 commercial samples, detecting 6 that were incorrectly labelled (30%). Therefore, this molecular tool could be applied in questions related to correct labelling, traceability, and import control of products containing the taxonomic groups studied.     

秘鲁鱿鱼烤制过程中的水分及质构变化

鱿鱼丝是现代人喜爱的休闲食品,烤制是鱿鱼丝加工中的关键工序,对鱿鱼的品质有重要的影响。本文主要研究了烤制过程中秘鲁鱿鱼的水分、质地、色泽的变化。结果表明,随着烤制时间的延长,秘鲁鱿鱼的水分含量和水分活度降低,损失的主要为中间水和结合水;烤制过程中鱿鱼肉的硬度、咀嚼性、粘着性均有很大程度的提高,弹性下降。      

Characterization of Moringa oleifera leaf and seed protein extract functionality in emulsion model system

This study provides a comparative overview of Moringa oleifera leaf and seed protein extract (LPE and SPE, respectively) functionality in emulsions. Raw seed cake (RS) had more protein (45.8%) than raw leaf (RL) (27.4%). RL comprised higher polyphenol and flavonoid content than RS, Granny Smith apples, and Goji berries. Protein functionality data revealed that LPE had excellent solubility, and emulsifying properties than SPE at pH 7.0. In contrast, SPE had relatively strong surface hydrophobicity. At pH 7.0, leaf extract emulsions (LEE) possessed relatively small particle size distribution, strong negative charge, excellent stability, and minimum sedimentation velocity. On contrary, at pH 3.5, particle size, and velocity increased, contributing to monodisperse sedimentation. Seed extract emulsions (SEE) had an overall large particle size and demonstrated fast and extensive creaming and sedimentation at both pH conditions. Our findings indicate that M. oleifera leaf protein extracts have considerable potential for use in emulsion-based foods.     

Pea protein isolates: Structure,extraction, and functionality

In keeping with emerging consumer trends, the food industry is continually searching for cheaper and healthier protein ingredients to replace those derived from animal sources (e.g., whey, casein, gelatin, and ovalbumin), gluten-based proteins (e.g., wheat), and soy. Pea protein shows promise in filling this niche because it is non-genetically modified organism (GMO), gluten-free, nutritious, and of low allergenicity. This review discusses structure–function relationships of pea protein isolates, the impact of extraction techniques used to produce the isolate, and the impact of cultivar and environment on ingredient performance in terms of solubility, water- and oil-holding capacities, emulsifying, foaming, and gelation properties.     

Effect of camel chymosin on the texture,functionality, and sensory properties of low-moisture,part-skim Mozzarella cheese

The objective of this study was to compare the effect of coagulant (bovine calf chymosin, BCC, or camel chymosin, CC), on the functional and sensory properties and performance shelf-life of low-moisture, part-skim (LMPS) Mozzarella. Both chymosins were used at 2 levels [0.05 and 0.037 international milk clotting units (IMCU)/mL], and clotting temperature was varied to achieve similar gelation times for each treatment (as this also affects cheese properties). Functionality was assessed at various cheese ages using dynamic low-amplitude oscillatory rheology and performance of baked cheese on pizza. Cheese composition was not significantly different between treatments. The level of total calcium or insoluble (INSOL) calcium did not differ significantly among the cheeses initially or during ripening. Proteolysis in cheese made with BCC was higher than in cheeses made with CC. At 84 d of ripening, maximum loss tangent values were not significantly different in the cheeses, suggesting that these cheeses had similar melt characteristics. After 14 d of cheese ripening, the crossover temperature (loss tangent = 1 or melting temperature) was higher when CC was used as coagulant. This was due to lower proteolysis in the CC cheeses compared with those made with BCC because the pH and INSOL calcium levels were similar in all cheeses. Cheeses made with CC maintained higher hardness values over 84 d of ripening compared with BCC and maintained higher sensory firmness values and adhesiveness of mass scores during ripening. When melted on pizzas, cheese made with CC had lower blister quantity and the cheeses were firmer and chewier. Because the 2 types of cheeses had similar moisture contents, pH values, and INSOL Ca levels, differences in proteolysis were responsible for the firmer and chewier texture of CC cheeses. When cheese performance on baked pizza was analyzed, properties such as blister quantity, strand thickness, hardness, and chewiness were maintained for a longer ripening time than cheeses made with BCC, indicating that use of CC could help to extend the performance shelf-life of LMPS Mozzarella.     

Relationship between water content, NaCl content, pH and texture parameters in dry-cured muscles

The aim of the present study was to describe the effect of NaCl and pH on the relationship between water content and hardness, cohesiveness and springiness in dry-cured muscles. The experiment was undertaken using 18 hams, selected in a commercial slaughterhouse. Half of the hams had a pH < 5.7 and the rest a pH > 6.2, measured on the semimembranosus muscle at 24-h postmortem. The semimembranosus and biceps femoris muscles were cut from hams, cured and individually packaged in bags and were laid in trays in a room at 2 ± 2 °C for 45 days. Thereafter nine samples from each muscle were shaped like a parallelepiped and dried until different levels of drying, ranging from 28.5% to 59.7% water content, were attained. The rest of the muscle was ground and packaged until its subsequent physicochemical analysis. At the end of the drying period, a Texture Profile Analysis was used to determine textural parameters. The results indicated that for a range of X (kg H₂O/kg dry matter) between 0.8 and 1.3 the hardness remains practically unchanged while for X < 0.6 the hardness increases substantially. The samples from hams with low pH_SM had greater hardness, cohesiveness and springiness than those from hams with high pH_SM. Dry-cured muscles with lower NaCl content showed lower hardness, cohesiveness and springiness, especially in those with pH_SM > 6.2. At X values lower than 0.6 the hardness was more influenced by water content than by NaCl content or pH_SM.     

秘鲁鱿鱼肌肉柔软质构改进技术的初步研究

秘鲁鱿鱼肌肉特性不同于紫鱿鱼,非常松软,不再适于采用北太紫鱿鱼的加工方法,因此研究秘鲁鱿鱼的肌肉质构改进技术,使之接近北太紫鱿鱼,从而满足市场需求,具有重大的现实意义.以冷冻的秘鲁鱿鱼为原料,以北太紫鱿鱼为参照.测定水分含量作为质构变化的指标,结合鱼体质构感官评定标准,时比了盐渍、糖渍、盐糖同时浸渍三种方法的改善效果,选择出改善质构的最佳方法.最佳的改进方法是:采用盐糖渍法.盐糖分步浸渍:先糖浓度8%,浸渍0.5h.再盐浓度5%,浸渍1.0h;或先盐浓度8%,浸渍0.5h,再糖浓度8%,浸渍1.0h.盐糖同时浸渍:盐浓度8%,糖浓度8%,浸渍0.5h;或者是盐浓度5%,糖浓度8%,浸渍1.0h.     

Effects of massaging time on texture, rheological properties, and structure of three pork ham muscles

Changes in texture parameters (hardness, cohesiveness, chewiness), rheological properties (elastic and viscous moduli), and structural elements (fibre cross-sectional area and thickness of peri- and endomysium) of three pork ham muscles: Biceps femoris (BF), Semimembranosus (SM), and Quadriceps femoris (QM), subjected to effective massaging for 2, 4, 6, 8, 10, 12 h were followed. BF, with its higher fibre cross-sectional area thicker peri- and endomysium, compared with QF and SM, was harder, more elastic, and more viscous than the other two muscles. Massaging resulted in an increase in the mean fibre cross-sectional area, changes in thickness of the peri- and endomysium, and a reduction in hardness and chewiness as well as in elastic and viscous moduli of the muscles studied. The lower were the initial values of textural and structural parameters and rheological properties of a muscle, the shorter massage time was necessary. To arrive at comparable values of textural parameters, rheological properties, and a similar sensory acceptance, BF, SM, and QF had to be effectively massaged for 12, 6, and 4 h, respectively.     

水分含量对软烤鱿鱼足片质构和色泽的影响

通过分析不同水分含量软烤鱿鱼足片的质构和色泽指标,探讨了水分含量与质构特性及色泽的相关性。结果表明:软烤鱿鱼足片质构特性中的硬度、胶粘性、咀嚼性随着水分含量的增加而降低,且呈现明显的线性关系,弹性亦随水分含量的升高而增加,内聚性基本不受水分含量的影响。L*随着水分含量的增加有上升的趋势,a*随着水分含量的增加亦有下降的趋势,但是差别都不显著(P>0.05),b*随水分含量的增加而降低,差别显著(P<0.05)。从用Lab和RGB颜色空间来看,水分含量为37%⁴3%时,制品色泽为黄色系,45%时制品色泽较差。从质地、色泽、口味和气味进行感官评定,确定水分含量为43%时制品质量最佳。     

Review: Soya protein products‐their processing,functionality, and application aspects

Abstract

Soya protein products are very interesting ingredients because of their ready availability, functionality, nutritional value, and price. This review covers the processing, functionality, and application of the various soya protein products, that is, full‐fat soya flours, defatted soya flours and grits, soya protein concentrates, soya protein isolates, textured soya products, and modified soya proteins. The choice of food manufacturers between these soya protein products depends on the functional properties, performance in the end products, and price. According to our experience soya protein concentrates offer a proven functionality at the right price, especially for applications in meat products. Soya protein products can help to meet the protein requirements of the modern food industry economically.     

鱿鱼水解物的抗氧化性及乳化性的研究

以鱿鱼为原料,经酶解后得到不同水解时间的水解物,研究不同鱿鱼水解物的抗氧化性、乳化性及起泡性变化.实验表明,随水解过程的进行,鱿鱼水解物DH逐渐增大,之后增加缓慢:对羟自由基清除活性和还原能力与DH呈正相关;对超氧阴离子和DPPH自由基清除活性呈先增加后基本不变的趋势;氮溶解指数逐渐增加.同时,经酶解的鱿鱼水解物较酶解前鱿鱼浆的乳化性、乳化稳定性及起泡性都发生了改变.     

Proteomic identification and physicochemical characterisation of paramyosin and collagen from octopus (Octopus vulgaris) and jumbo squid (Dosidicus gigas)

To perform improvements in food science, it is fundamental to understand the physicochemical properties of proteins since their interaction with other macromolecules plays an essential role in food systems. Collagen and paramyosin help in the maintenance of the matrix structure cells, the textural behaviour and the technical functionality of the protein concentrates; because of this, their identification and characterisation are necessary. Cephalopods species have shown differences in the distribution of its muscle fibres. The amino acid profile of jumbo squid showed a high content of glycine and hydroxyproline, while octopus showed a high content of acidic amino acids. The thermal profile of jumbo squid showed an endothermic transition at 117 °C, which octopus did not present. Moreover, the proteomic identification confirms the identity of paramyosin with 33% coverage to paramyosin from Dosidicus gigas and a 4% coverage to collagen type II from Sepia pharaonis on octopus and jumbo squid, respectively.     

Sensory, microbiological, physical and chemical properties of cuttlefish (Sepia officinalis) and broadtail shortfin squid (Illex coindetii) stored in ice

The objective of this study was to characterize whole raw cuttlefish (Sepia officinalis) and shortfin squid (Illex coindetii) during storage in ice through sensory, microbiological, chemical and physical analyses. The recently developed Quality Index Method (QIM) tables for these species were used for sensory analysis. Shelf-life of whole cuttlefish and shortfin squid were estimated as around 10 and 9 days, respectively, according to QIM, which is shorter than for most species, especially fish. The numbers of microorganisms found in cuttlefish and shortfin squid surfaces until rejection were lower than in fish, which suggest predominance of enzymatic (autolytic) degradation. H₂S-producing bacteria constituted a significant proportion of the spoilage flora. Physical analysis performed using the RT-Freshmeter and the Torrymeter showed these instruments can be applied to cuttlefish and shortfin squid, providing useful complementary information on the rates of change of electrical properties. Free tryptophan and VBN contents significantly changed during the first storage week indicating that low levels of these compounds could be used as indicators of fresh and high quality cuttlefish and broadtail shortfin squid. Urea can be useful as spoilage indicator for cuttlefish, as well as agmatine for broadtail shortfin squid. An overall look into data obtained shows, as expected, that spoilage of these cephalopod species can be considered a different phenomena when compared to fish and is not yet completely clarified.     

Towards potato protein utilisation: insights into separation,functionality and bioactivity of patatin

Potato fruit juice (PFJ) is a dilute industrial by-product of potato starch industry containing potato protein that is abundant in patatin, a major storage protein. From an economic standpoint, conversion of potato protein into a high value-added food ingredient has received considerable attention. In this review, the structural and physicochemical characteristics of patatin are introduced. The separation and purification methods of patatin are compared and summarised. The functional properties of patatin as food ingredients are comprehensively reviewed. The beneficial effects of patatin on health and food application are emphatically presented. In addition, the current challenges for development of patatin as a functional food ingredient are also discussed. This review offers a theoretical basis for further application of patain in the food industry.     

燕麦分离蛋白的提取及功能性测定

以裸燕麦为原料,采用传统的碱提酸沉法,在料液比为1∶10 g/mL,pH=8.5(碱提)和pH=4.5(酸沉),T=20℃条件下提取燕麦分离蛋白,蛋白提取率为75%,再在不同的pH、离子强度和蛋白浓度条件下,进行燕麦分离蛋白的功能性测定,测定其乳化活性、起泡性、持水性、粘度。结果得出,燕麦分离蛋白在等电点附近时其乳化活性、起泡性、持水性数值最低,离子强度对各功能性指标的影响各不相同,燕麦分离蛋白粘度与其蛋白浓度成正比。     

鱿鱼头蛋白酶水解物的抗氧化活性

采用Flavourzyme 500 MG蛋白酶对鱿鱼头蛋白进行酶解,制备不同水解度的水解物并测定水解物的抗氧化活性,分析鱿鱼头蛋白水解物的水解度与其抗氧化活性的相关性。结果表明:在水解度为0³9.80%范围内,随着水解度的逐渐升高,鱿鱼头蛋白酶水解物多肽含量和游离氨基酸总量逐渐增加,超氧阴离子自由基清除能力、DPPH自由基清除能力、羟自由基清除能力、还原能力、抗氧化能力和亚铁离子螯合能力逐渐升高;在水解度为39.80%时,酶水解物多肽含量和游离氨基酸总量分别为12.97 mg/mL和4.49 mg/mL,上述抗氧化活性指标均为最高,分别为40.04%、32.72%、45.4%、1.449、0.697 mg/mL和43.34%。表明鱿鱼头蛋白酶水解物具良好抗氧化作用,有着重要的应用价值。