Separation and pre-concentration of Sunset Yellow in beverages and effervescent vitamin C tablets by a new flotation technique prior to spectrophotometric determination

ABSTRACT

A new, simple, low cost, high efficiency, and rapid floating technique was developed for the determination of Sunset Yellow in beverage and effervescent vitamin C. The method is based on two main steps: 1)- formation of dye-surfactant complex by the addition of a cationic surfactant, cetyltrimethylammonium bromide, to the solution containing an anionic dye (Sunset Yellow) and 2)- flocculation of the dye-surfactant complex with the participation of sodium perchlorate as a coagulant followed by aggregation and enlargement of the flocs while floating at the top of the solution. After the extraction, separated and preconcentrated Sunset Yellow was investigated by spectrophotometric determination. IR spectrum, scanning electron microscopy (SEM), and light microscopy were used to characterise the flocs. The effects of different parameters such as pH, concentration of surfactant, concentration of sodium perchlorate, and temperature on the extraction of dye were investigated and optimized. Under optimum conditions, a linear calibration curve was obtained in the range of 0.05–5 mg L^?1. The detection limit (3S_b/m) was 0.02 mg L^?1 with a preconcentration factor of 25. The relative standard deviation (RSD) for 0.1 mg L^?1 of Sunset Yellow was 2.6% (n = 10). The applicability of the method was evaluated by measuring the amount of dye in beverage and effervescent vitamin C. Interferences of typical cations and anions which may participate in the matrices were also checked. The amount of Sunset Yellow found in real samples was 1.32–3.89 mgL^?1.     

Pea pod, broad bean pod and okara, potential sources of functional compounds

Disposal of by-products generated by plant food processing represent an important problem in the industry, but these by-products are also promising sources of compounds which may be used for their technological or nutritional properties, and today they are considered as a possible source of functional compounds. This work has contributed to the knowledge of three legume by-products, pea pod (Pisum sativum L.), broad bean pod (Vicia faba L.) and okara from soybean (Glycine max L.). These three by-products have in common that their major fraction is dietary fibre (pea pod: 58.6 g/100 g; okara: 54.3 g/100 g; broad bean pod: 40.1 g/100 g). Sucrose, glucose and fructose are the most important soluble sugars in both pods; however α-galactosides (stachyose and raffinose) are in greater concentration in okara. Protein is also a considerable component, although in higher amount in okara than in pods. Okara presents a large quantity of fat however both pods show similar low contents. Linoleic acid is the most important fatty acid; oleic acid is remarkable in okara and pea pod and linolenic acid in broad bean pod. Mineral amount is major in by-product pods than in okara, and the most important minerals are potassium, calcium and iron.     

啤酒酵母自溶物乳酸发酵饮料的研究

在啤酒废酵母自溶物中，添加少量葡萄糖，经乳酸菌作用制成一种新型饮料，探讨了菌种选择、发酵时间、发酵温度和最佳工艺参数。结果表明：酵母自溶物加0.5%葡萄糖，植物乳杆菌和片球菌按比1：1接种，30℃发酵10h，可制得一种鲜香酸甜的乳酸饮料。     

豆渣在食品工业中的利用

豆渣虽是豆制品之残渣，但富含营养素，尤以含有纤维素为独特。而纤维素是人体保健之必需。豆渣来源广，价格低，开发以豆渣为原料的多种食品和食品添加剂已在国内外初见成效，本文介绍了豆渣在不同方面及不同功能的利用、制作的详细方法。     

我国酒店核心竞争力探析

核心竞争力能使企业在创造价值和持续发展方面、在提高各种资源的运营效率方面比竞争对手做得更好.在我国酒店业面临外资酒店的强劲挑战和激烈的竞争情况下,将企业核心竞争力理论引入酒店的经营管理中,可以培育中国酒店的核心竞争力.     

HG-1944/24.7-PM6型锅炉大板梁的吊装

文章从吊装机械选择、布置、负荷分配及净空计算入手,到垂直度、同步性、就位三大措施,描述了该工程锅炉大板梁的吊装方案。     

自动冲饮机的控制系统方案设计

为了实现自动冲饮机展示自动控制技术及多种传动方式的要求,对控制系统的硬件和软件设计进行了深入的讨论;在分析出系统的控制方式为通断控制以后,提出采用可编程逻辑控制器作为系统的控制核心,确定了控制系统硬件结构,给出了软件流程图,并采用模块化方法编写了可编程逻辑控制器程序. 在控制系统中增加了客户机和服务器,并利用网络通讯技术和串行通讯技术实现了一种下位机柨突Щ鷸服务器的三级监控系统设计方案, 现场运行情况良好.     

分光光度法同时测定饮料中微量钙,镁

本文研究用偶氮氟磷Ⅰ为显色剂,用分光光度法同时测定饮料中微量钙和镁的方法,得出了合理的试验条件,用于饮料分析,取得了满意的结果.     

UHT-Sterilized Peanut Beverages: Kinetics of Physicochemical Changes during Storage and Shelf-Life Prediction Modeling

Strawberry-flavored (S04) and chocolate-flavored (C04 and C20) peanut beverages UHT-sterilized (137 °C, 4 sec or 20 sec) and aseptically filled in Tetra Briks were stored for 6 mo at 5, 20 and 35 °C. Sensory characteristics and kinetics of physicochemical changes were studied. The changes were of zero (pH of S04, and sedimentation and homogenization indices of all beverages) and first (pH of C04 and C20, viscosity and color lightness of all beverages) order. Reaction rate constant and Gibb's free energy increased with temperature. Activation energy followed Arrhenius equation. Deterioration in beverage sensory qualities highly correlated with increase in sedimentation index and decrease in pH and emulsion stability. Shelf-life prediction models were constructed based on sensory and kinetics data. The shelf-life was estimated to be 4–7 mo for beverages stored at 30–35 °C.     

基于EJB 技术的网络教学系统的设计与实现

分析了网络教学系统的总体需求,运用实体EJB、会话EJB进行组件设计,说明了系统的设计原则与系统的主要功能.