Effect of Spirulina addition on the physicochemical and structural properties of extruded snacks

Abstract Nowadays the demand for practical food like snacks increases worldwide, however the nutritional value in most these formulations is reduced. Due to its chemical composition with high protein concentration, the microalga Spirulina has been used on the production of enriched foods. The present study aimed to evaluate the effects of Spirulina sp. LEB 18 addition on snacks formulations and extrusion conditions on the physicochemical and structural properties of snacks. Protein concentration and physical properties such as expansion index, bulk density, hardness, water absorption index, water solubility index and color were determined. The results showed that the addition of Spirulina sp. LEB 18, temperature in the last zone of the extruder and feed moisture influenced the product responses. The increase in feed moisture increased the hardness, bulk density and water absorption index of the snacks. Higher concentrations of microalga produced snacks with higher protein content, total color difference (ΔE) and compact structure. The addition of 2.6% Spirulina produced snacks with up to 11.3% protein and with adequate physical and structural properties for consumption. Thus, snacks containing Spirulina are an alternative to the demand for healthy food of practical consumption.

摘要 如今，全球范围内即食类食品（如零食）的需求持续增长，但多数此类产品配方的营养价值却有所降低。由于螺旋藻（Spirulina）的化学成分中蛋白质含量较高，其已被用于营养强化食品的生产中。本研究旨在探究添加螺旋藻（Spirulina sp.）LEB 18对零食配方的影响，以及挤出工艺条件对零食理化与结构特性的作用。研究测定了零食的蛋白质含量，以及膨化指数、堆积密度、硬度、吸水指数、水溶性指数与色泽等物理特性。结果表明，螺旋藻（Spirulina sp.）LEB 18的添加量、挤出机末段温度与进料含水率均对产品响应指标存在影响。进料含水率的提升会提高零食的硬度、堆积密度与吸水指数。微藻添加量越高，制得的零食蛋白质含量、总色差（ΔE）越高，且结构越致密。添加2.6%的螺旋藻可制得蛋白质含量达11.3%的零食，且其物理与结构特性符合食用要求。因此，添加螺旋藻的零食可满足消费者对即食健康食品的需求，是一种可行的产品方案。