Instrumental and sensory evaluation of cooked pasta during frozen storage

Food consumption patterns have changed significantly during the last years, showing an increase in the consumption of convenience foods. Frozen foods represent an important segment of this market. The aim of the present paper was to study the influence of frozen storage on the quality of cooked organic tagliatelle. Instrumental measurements of different quality parameters (moisture content, colour, textural and rheological characteristics of frozen cooked pasta) were performed during twelve months of storage. The sensory properties of pasta were also evaluated by means of an acceptability study. In general, both instrumental and sensory analysis found that frozen storage affects negatively the acceptability of cooked pasta. The advantages obtained through fast freezing procedures are not maintained along storage, being hardness (instrumental) and consistency (sensory) the most relevant quality indices. Finally, the shelf life of the product was calculated as 3.6 and 3.8 months in the cryogenic device and air‐blast tunnel, respectively, based on simple kinetic models.     

Sustainable recovery of grape skins for use in an apple beverage with antiglycation properties

An apple puree formulated with red grape skins was developed on pilot scale as a new beverage with antiglycation properties. The addition level of grape skins was selected by a liking test with 70 consumers. The selected formulation was a fibre‐rich source and delivered grape anthocyanins, flavonols and flavanols resulting in ~ twofold higher antiglycation activity than the apple puree. Pasteurisation (3‐D in the target microorganism Alicyclobacillus acidoterrestris) did not affect the antiglycation activity, which decreased by 30% upon sterilisation. Storage for 1 month in the temperature range 15–35 °C affected the contents of anthocyanins, monomeric, dimeric and oligomeric flavanols, while chlorogenic acid, flavonols and dihydrochalcones were stable. About 90% antiglycation activity was retained after one‐month storage at 15 °C. The use of red grape skin as ingredient could represent an opportunity for the apple processing industry to develop a value‐added product.     

Influence of phytosterol and phytostanol food supplementation on plasma liposoluble vitamins and provitamin A carotenoid levels in humans: An updated review of the evidence

Phytosterols and phytostanols (PAP) compete with cholesterol absorption in the intestine, resulting in a 5–15%-reduction in plasma total and LDL cholesterol. An important issue is the PAP potential to reduce the plasma concentrations of fat-soluble vitamins and provitamin A carotenoids. Here, an update of the scientific evidence is reviewed to evaluate plant PAP-enriched foods impact on plasma fat-soluble vitamins and carotenoid levels, and to discuss potential implications in terms of cardiovascular risk. Based on 49 human interventional and 3 bioavailability studies, results showed that regular consumption, particularly over the long term, of foods fortified with PAP as recommended in labeling does not significantly impact plasma vitamins A, D, and K concentration. A 10% significant median reduction was observed for α-tocopherol. Concerning carotenoids, while 13 studies did not demonstrate statistically significant plasma β-carotene reduction, 20 studies showed significant reductions, with median effect size of ?24%. This decline can be mitigated or offset by increased fruits and vegetables consumption. Furthermore, higher cardiovascular risk was observed for differences in plasma β-carotene concentration of the same magnitude as the estimated average decrease by PAP consumption. These results are supported by the only study of β-carotene bioavailability showing decrease in absorption by phytosterols daily intake.     

Comparison of 3 Spectrophotometric Methods for Carotenoid Determination in Frequently Consumed Fruits and Vegetables

ABSTRACT: Carotenoids are C-40 tetraterpenoid compounds with potential health beneficial effects. Major dietary sources include a variety of fruits and vegetables. Rapid screening methods are therefore desired, but their accuracy varies depending on the carotenoid profile and the matrix of the plant food. In the present study, 3 different methods were compared, all based on a rapid extraction protocol and spectrophotometric measurements to determine the total amount carotenoids present in fruits and vegetables (n = 28), either with or without chlorophyll. Published methods (a) Lichtenthaler and (b) Hornero-Méndez and Mínguez-Mosquera were compared with a newly developed method (method c) based on the average molar absorption coefficient (135310 Lcm⁻¹mol⁻¹) and wavelength (450 nm in acetone), for the 5 predominant carotenoid species (beta-carotene, zeaxanthin, lycopene, lutein, beta-cryptoxanthin) in the investigated foods. All results were compared to HPLC (method d). To avoid overestimating carotenoid concentrations due to chlorophyll A and B presence, the effect of saponification was studied for all methods. Overall, saponification led to significant carotenoid losses (12.6 ± 0.9%). Methods a, b, c, and d yielded 5.1 ± 0.4 mg/100 g, 4.6 ± 0.5 mg/100 g, 4.3 ± 0.5 mg/100 g, and 4.2 ± 0.5 mg/100 g total carotenoids, respectively, with method a leading to significant higher mean concentrations compared to all other methods (P < 0.001, Bonferroni) with methods b and c being not significantly different and highly correlated compared to HPLC (> r = 0.95). Similar results were found when stratifying for chlorophyll content and fruits compared with vegetables, however, accuracy varied for individual fruits, highlighting the limitation to use the same method for all plant foods. Practical Application: This study presents a comparison of various rapid spectrophotometric measurements to determine total carotenoid content in various fruits and vegetables and could aid in the selection of the appropriate method for individual plant foods with different carotenoid profile and matrices.     

婴幼儿配方食品和乳粉中维生素B2的测定

采用高效液相-二极管阵列检测器检测婴幼儿配方食品和乳粉中核黄素(维生素B2),样品在稀盐酸环境中高温水解、酶解,经C18反相色谱柱分离,流动相为乙酸钠(pH=4.5)-甲醇(体积比为65∶35),检测波长为450nm。本方法中维生素B2线性范围为0~26.5μg/mL,检出限为0.02μg/mL。维生素B2平均加标回收率为94.0%,维生素B2相对标准偏差为0.44%,合成标准不确定度为4.917×10-3。该方法简单、快速、测定干扰小,结果与国家标准测定方法比较无显著性差异。     

Factors affecting the suitability of aluminium-foil trays for microwave oven heating: Comparison with plastic trays

The suitability of shallow aluminium trays (thickness of food layer 20 mm) for heating of different casseroles in microwave ovens was extensively studied. The effects of the shapes and sizes of the trays, the initial temperature and the type of oven were tested systematically for the usability of the aluminium trays, the required heating time and heating results. The results were compared with those obtained using CPET trays. It was also investigated whether incorrect placing of an aluminium tray in the oven would cause risk situations, such as arcing. It was found that, when used correctly, aluminium trays are suitable for heating of both frozen and chilled casserole products in a microwave oven. Especially in the case of frozen products, aluminium trays are more suitable than plastic trays. The post-heating quality can be improved by packaging of foods in an aluminium tray instead of a plastic tray. The shape of the trays also has an important role. Aluminium trays are better suited than plastic trays for heating in a combination oven.     

Effect of Frozen Storage on the Gel-forming Properties of Hoki (Macruronus novaezelandiae)

The possibility of using frozen hoki to make surimi was investigated. At intervals, fish were thawed under controlled conditions and gels were then made from minces of the flesh. Both puncture and torsion tests showed the quality of gels declined with duration of storage of frozen hoki. This decline was matched by a decrease in pH and an increase in formaldehyde concentration in the frozen flesh. The data suggest a land-based surimi plant could not be operated outside the harvesting season to any appreciable extent using frozen hoki stored at -29°C.     

Linear Heating Rate Affects Gelation of Alaska Pollock and Pacific Whiting Surimi

Shear stress of Alaska pollock surimi gels with and without beef plasma protein (BPP) increased as heating rate decreased, but shear strain was unaffected. An increase in shear stress was accompanied by an increase of cross-linked myosin heavy chain. Slow heating rates increased proteolysis in Pacific whiting surimi as shown by degradation of myosin heavy chain and low shear stress and shear strain. Proteolysis of whiting surimi was lessened by BPP to a greater extent at rapid heating rates (20 and 30°C/min) than at slow heating rates (1 and 5°C/min).     

发酵法在淡水鱼鱼糜脱腥中的应用研究

利用活性干酵母发酵法对淡水鱼鱼糜进行脱腥，选择接种量、温度、时间、和pH四因素进行正交试验，以感官评定结果和三甲胺含量作为评价指标，优化了该法脱腥的最佳工艺条件。结果表明，当酵母接种量为2．00％、pH6．65、温度35℃下加热30min，脱腥效果最好，由此加工制成的鱼糜制品产品品质良好。