Effects of housing system and age of laying hens on egg performance in fresh pasta production: pasta cooking behaviour

BACKGROUND: Very few studies concern the effects of layer housing systems and age on egg technological properties. Thus the aim of this work was to study the influence of these two factors on egg performance in fresh pasta production, focusing on pasta cooking behaviour. Samples of pasta subjected to analysis were prepared with eggs laid by Hy‐Line Brown hens (from 27 to 68 weeks old) housed in cage, barn and organic systems. RESULTS: Higher average values of weight increase and matter loss during pasta cooking were observed for samples prepared with eggs laid by older hens. Such cooking behaviour indicated the development of a weaker pasta protein network, resulting from a decrease in the quantity of albumen protein and an increase in fat content, which is due to the reduction in albumen/yolk ratio during hen aging. The housing system had a significant effect only on matter loss in cooking water, but differences between samples were so small as to be unlikely perceived by consumers. CONCLUSION: Both hen age and housing system significantly affected pasta cooking behaviour, but the greatest effect was exerted by the hen age. Copyright © 2010 Society of Chemical Industry     

Role of pasteurisation heat treatments on rheological and protein structural characteristics of fresh egg pasta

The influence of egg pasteurisation and of thermal treatment(s) of fresh egg pasta on the protein network in the pasta were studied. Protein structural parameters were correlated with the physico-chemical and rheological characteristics of pasta. Twelve samples of fresh egg pasta were laboratory-produced, using raw or pasteurised whole egg, and either left untreated or submitted to one or two pasteurisation processes. Industrial pasteurisation of the eggs did not affect the protein network of pasta or its rheological and functional characteristics. Double thermal pasteurisation of egg pasta deeply influenced its structural characteristics, due to the formation of a tight protein network stabilised by disulfide bonds, in which ovalbumin plays an essential role. This tight protein network affected the cooking behaviour and the rheological properties of fresh egg pasta, decreasing weight increase upon cooking and break strain, while increasing break load and Young modulus. The indexes derived from these studies were applied to the characterisation of 24 commercial samples of fresh egg pasta. By using the Young modulus before and after cooking (rheological parameters) and protein solubility in buffer-saline (structural parameter), it was possible to discriminate three groups of samples as a function of the severity of their thermal treatment.     

Gluten-free pasta production from banana and cassava flours with egg white protein and soy protein addition

Egg white protein and soy protein were incorporated into a banana and cassava flour blend (75:25) to produce gluten-free pasta. The objectives of study were to investigate the effects of the different protein sources on the physico-chemical properties of gluten-free pasta. The levels of protein inclusion were 0%, 5%, 10% and 15% of composite flour (w/w) for each type of protein. Pasta made from 100% durum wheat semolina was used as controls. The protein fortification affected the total starch, resistant starch and protein content of gluten-free pasta compared to semolina pasta. No significant effects of soy/egg white protein addition were found in either insoluble or soluble dietary fibre content. Cooking properties of pasta (optimum cooking time, swelling index, water adsorption index and cooking loss) and texture properties (firmness and extensibility) were affected by the level of protein addition and the type of protein. Results showed the utilisation of 25% cassava flour and protein inclusion have a promising application in gluten-free pasta production.     

Development of gluten-free fresh egg pasta analogues containing buckwheat

To improve the use of common buckwheat (Fagopyrum esculentum), characterized by interesting nutritional properties, it could be used in pasta formulations. In particular, as buckwheat is devoid of the gluten-forming proteins, it might be an ingredient for celiac patient food. The aim of this study was to develop both fresh egg pastas integrated with buckwheat and fresh egg pasta analogues classifiable as gluten-free, based on buckwheat and rice flours. Matter loss in the cooking water and weight increase during cooking of buckwheat pasta were higher than those of a reference sample made of common wheat flour. As buckwheat integration increased, sample break strain was significantly lower, as a result of the progressive reduction in gluten content. In the production of gluten-free pasta analogues, wheat flour was substituted with rice flour, precooked rice flour or pregelatinized rice starch. Since samples containing precooked rice flour gave the best results, in terms of workability, break strain and weight increase during cooking, they were also produced on an industrial scale. Industrial gluten-free fresh egg pasta analogues were tougher and less deformable in comparison with the laboratory-produced samples. These results were determined by the presence of the double thermal pasteurisation treatment, which allows to obtain a better structure of the product, showing also a lower matter loss during cooking.     

Mechanical and rheological properties of fresh egg pasta as affected by shell egg production factors

The aim of this work was to study the influence of hen age and housing system on egg performances in fresh pasta production, focusing on mechanical and rheological properties of pasta. Samples of pasta were prepared with eggs laid by Hy‐Line Brown hens (from 27 to 68 weeks old) housed in conventional cage, barn and organic systems. Only hen age significantly affected pasta properties. In particular, as regards raw pasta, the loosest structure was obtained using eggs laid by the youngest hens (27–30 weeks old). On the contrary, in cooked pasta, the weakest structure was observed when eggs were laid by hens aged 53–68 weeks. However, differences, although significant, were small and thus most likely not sensorially perceivable. Significant correlations were found between mechanical and rheological properties of raw fresh egg pasta, meaning that small deformation measurements are as valuable as large deformation tests for the characterisation of this product.     

Cholesterol oxidation in pasta produced with eggs of different origin

Cholesterol oxidation was studied in 12 samples of mass-produced egg pasta and in home-made egg pasta produced with fresh eggs obtained from hens bred in the open with organic methods (a), fresh eggs purchased in a local retail shop (b) and spray-dried eggs, which are not allowed by Italian law (c). The lipids of commercial egg pasta contained almost twice the concentration of cholesterol of hand-made egg pasta (2.6 vs. 1.4 mg/100 mg lipids). Mass-produced egg pasta contained 2.2±1.5 g oxycholesterols (cholesterol oxidation products, or COPs)/g of pasta, Epo being the most represented oxycholesterol. The oxycholesterol content in home-made pasta was 1.7, 3.5 and 3.6 g/g pasta, for pasta obtained with samples a, b and c, respectively. 7-Hydroxycholesterol and -epoxy-cholesterol were not taken in account, because they co-eluted with campesterol and campestanol, respectively. The home-made procedure (eggs mixed with flour and water and dried for 48 h at 30 °C) led to the formation of 7 k and 7, rather than Epo. The use of eggs from hens bred in the open reduced the COPs content considerably. The home-made product should be consumed within a few days after manufacturing or should be immediately refrigerated.     

Evaluation of isoflavone content and antioxidant activity of soy-wheat pasta

The purposes of this work were to determine isoflavones profile and antioxidant activity of two soy flours and spaghetti produced from semolina blended with increasing amount of these flours. Defatted and toasted soy flour (DSF and TSF, respectively) showed different isoflavone profiles though glucosides were the most abundant isoflavone forms in both the meals. The pasta-making procedure determined an increase of the aglycone forms that was at least 37 and 21% in TSF and DSF pasta, respectively. Cooking operations induced severe decreases of the isoflavone content (the losses ranged from 60.44 to104.91 mg kg⁻¹ for TSF pasta and from 85.41 to 469.33 mg kg⁻¹ for DSF pasta). The results of the antioxidant activity were quite different as a function of the methods applied but they resulted generally well correlated with the isoflavone contents of the samples. Cooking induced significant decreases of the antioxidant activity in almost all samples. This result appears well correlated with the decrease of the total isoflavone content and the presence of antioxidant activity in the cooking water.     

Development of a rapid, non-destructive method for egg content determination in dry pasta using FT-NIR technique

A quick, non-destructive method, based on Fourier transform near-infrared (FT-NIR) spectroscopy for egg content determination of dry pasta is presented. Multivariate calibration was carried out by using partial least squares (PLS) regression. A calibration set of 108 samples, a validation set of 22 samples and a prediction set of 11 samples of egg pasta were used. The diffuse reflection spectra of different types of pastas were measured by FT-NIR analyzer in the 800-2500 nm spectral range. The optimal results for egg content (root mean square error of prediction (RMSEP) = 0.7; R² = 90.7, Rank = 4) were obtained when the spectra were subjected to the first derivation combined with multiplicative scatter correction (MSC) and smoothing. Egg content was determined from FT-NIR results by introducing a mathematical correction step.     

Effects of rice properties and emulsifiers on the quality of rice pasta

Two commercial rice flours (GTIndica and GTJaponica, with amylose contents of 306.8 and 185.2 g kg^?1 respectively) and their blended flours were used to make rice pasta. The effects of two emulsifiers (distilled glyceryl monostearate (GMS) and a commercial emulsifier (KM3000)) on the pasting and thermal properties of dried rice pasta were investigated using a Rapid Visco Analyser (RVA) and a differential scanning calorimeter (DSC). The rice pasta made from high‐amylose rice flour had better extrusion properties, better texture, whiter colour, less cooking loss and better eating quality than that made from low‐amylose rice flour. The maximum amount of low‐amylose rice flour that could be blended in for making an acceptable quality of rice pasta was 500 g kg^?1. A soft texture, low adhesiveness and low gumminess of cooked rice pasta were obtained by adding 10 g kg^?1 GMS. SEM investigations showed that use of an emulsifier restricted the swelling of starch granules, especially for the pasta made from high‐amylose rice flour. © 2001 Society of Chemical Industry     

Changes in durum wheat kernel and pasta proteins induced by toasting and drying processes

Durum wheat kernels were subjected to a toasting process and the proteins characterised by size exclusion-high performance liquid chromatography (SE-HPLC) and sodium dodecyl sulphate–polyacrylamide gel electrophoresis. With this physical process, albumins and globulins, as well as glutenins and gliadins, polymerised as seen by a shift of the SE-HPLC profile to lower elution times. The polymerisation seemed to happen mainly through disulphide bonds, even though the participation of ω-gliadins to the aggregation suggested the involvement of other kinds of interactions. It led to the revelation of a new peak originated by thermal aggregation of small polymeric proteins. The changes in the chromatographic profile were accompanied by increasing amounts of total unextractable polymeric proteins. The replacement of semolina with toasted durum wheat flour (5%, 10%, 15%, 20% and 30%) for the production of pasta in the shape of spaghetti significantly (p < 0.001) affected the molecular size distribution of the polymeric proteins, even though the replacement of semolina with 5% and 10% of toasted durum wheat flour (TDWF) did not significantly (p > 0.05) change the unextractable polymeric proteins (UPP) when compared with spaghetti made with 100% durum semolina. On the other hand, the replacements of semolina with 15–30% TDWF showed significant (p < 0.001) increase in UPP when compared with 100% durum semolina spaghetti.     

Determination of the herbicide isoproturon in cereal grains and pasta by LC with LC/MS confirmation

A method was developed for the determination of the herbicide isoproturon in wheat, maize, oats and pasta, with a limit of determination of 0.05 mg kg^-1. Isoproturon was extracted from moistened samples using a mixture of acetone, hexane and dichloromethane. The resulting extract was cleaned-up by solid-phase extraction using aminopropyl-bonded silica cartridges and analysed by reversed-phase liquid chromatography with photodiode array detection. Confirmation was by electrospray liquid chromatography-mass spectrometry. Recoveries from seven samples of each of the four matrices spiked with isoproturon at 0.05 and 0.5 mg kg^-1 were in the range 88-104%. The method was used to monitor cereal grains and pasta as part of the UK food monitoring programme.     

Improvement of cooking quality of maize pasta products by heat treatment

A new process has been developed to manufacture good pasta products from a blend of durum wheat semolina and maize flour (ratio 33: 66). It consists of submitting, to a high temperature (90 to 120°C) for 90 to 180 min, pasta previously processed and dried under the usual industrial conditions. Colour characteristics (yellowness, brownness and red index) are not affected when the treatment is kept below 100°C; at a higher temperature the red index increases sharply. There is a distinct improvement in cooking quality (cooking losses, surface condition) and this is inversely related to the water content of the pasta before treatment. The viscoelasticity of cooked pasta is dramatically modified when the temperature of treatment is 120°C.     

Drying kinetics of whole durum wheat pasta according to temperature and relative humidity

Drying kinetics of bran-free and bran-rich pasta (whole durum) was determined according to temperature (40, 60 or 80 °C) and relative humidity (65%, 75% or 85%). Compared to temperature, relative humidity in drying chamber had a greater effect on pasta effective moisture diffusivity (α<0.01), and both parameters responded to a modified Arrhenius-type equation. Activation energy of pasta (11.4 kJ mol⁻¹) was lower than reported in the literature. Bran changed the course of pasta drying, depending on temperature and relative humidity. When relative humidity was higher than 75%, effective moisture diffusivity of bran-rich pasta decreased but the reverse was observed below 75%. Above 76 °C, equilibrium moisture content of bran-rich pasta was higher than bran-free pasta. In conclusion, optimal drying conditions for bran-rich pasta were different than standard (bran-free) pasta. Close control of relative humidity in pasta drying unit would be critical, especially under high relative humidity and high temperature conditions.     

Relationship between gluten strength and pasta firmness in Indian durum wheats

Selected Indian durum wheats including five newly released varieties and seven landraces were studied for their grain quality, gluten strength (sodium dodecyl sulphate‐sedimentation and mixograph) and pasta making properties. Landraces were found to have good grain size, protein content, and gluten strength but they had lower test weight and semolina yield than released varieties. As protein composition affects gluten strength, landraces having combination of low molecular weight (LMW‐GS) with 5, 12, 15 and 19 linked to Gli‐B1 43.5 and high molecular weight (HMW‐GS) 2*, 14 + 15 provide a dough strength comparable with the 7 + 8 and LMW‐GS 2, 4, 6, 12, 15 and 19 (caa) allelic pattern, typically associated with good gluten strength. Landraces have rare combinations of glutenins and gliadins, which are not seen in commercial Indian durums, and in some cases, these rare alleles seem to favour good gluten strength and pasta firmness. Introduction of these alleles through breeding should improve the gluten strength and pasta making properties of Indian durum cultivars.     

鸡蛋中的生物活性蛋白质和肽

鸡蛋富含生物活性蛋白质,经酶解后也会产生多种生物活性肽,具有多种生理功能,如抑菌、抗高血压、抗氧化、促生长和增强免疫等作用。该文综述了鸡蛋中的生物活性蛋白和肽的研究进展。     

The role of a low molecular weight glutenin fraction in the cooking quality of durum wheat pasta

Durum wheat glutenin fractions, composed of two low molecular weight proteins DSG-1 and DSG-2 (durum wheat (Triticum durum Desf) sulphurrich glutenin fractions) were extracted from semolina samples using a low concentration of Na tetradecanoate after extracting albumins, globulins and gliadins. DSG proteins have a high? SH plus S? S content. A highly significant correlation was found between the ? SH plus S? S content of this DSG-rich fraction and the cooking quality of pasta (0.63, P <0.01 with firmness and 0.86, P <0.001 with the state of the surface of the cooked pasta) and this seems to be a functional relationship. The use of acetic acid at various molarities showed the presence of high molecular weight glutenin fractions with differing solubility properties. In this respect, differences were found between varieties which are placed in the same group according to the classification of durum wheats based upon the composition of high molecular weight glutenin subunits.     

The sulphydryl plus disulphide content in the proteins of durum wheat and its relationship with the cooking quality of pasta

Semolina samples were obtained from several durum wheat cultivars. The cooking quality of the spaghetti prepared from the semolina showed both inter and intravarietal differences. Proteins from semolina were extracted sequentially and both the reactive and total ? SH plus S? S content of the protein extracts determined amperometrically. The albumin-globulin fractions contained the highest amounts of both reactive and total ? SH plus S? S groups. The total ? SH plus S? S content was higher in the gliadins than in the glutenins but the latter contained higher amounts of reactive ? SH plus S? S groups. A highly significant correlation was found between the total amount of ? SH plus S? S content of the glutenins and the cooking quality of the samples (r=0.835): This might be a functional relation.     

间接ELISA检测不同贮存条件下花生中黄曲霉毒素B1

建立了一种利用间接ELISA检测花生中黄曲霉毒素B1的方法,同时考察了平衡相对湿度及贮存时间对花生中黄曲霉毒素B1(AFB1)含量的影响。结果表明:该方法的重现性好,AFB1回收率在95.20%~97.75%之间,线性范围为0.049~0.971μg/kg,最低检出限为0.029μg/kg;花生中AFB1的含量随平衡相对湿度的升高而增加,随贮存时间延长,其含量也不断增加。但平衡相对湿度低于57.6%时,即使贮存90 d,花生中的AFB1含量仍低于国家食品安全标准限量(20μg/kg)。