挤压加工条件对膨化食品中油脂品质影响
Effect of extrusion conditions on lipid quality in puffed food
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摘要: 膨化食品中的油脂品质在挤压加工过程中易发生变化,从而影响膨化食品品质。为生产健康营养型膨化食品,本文选择棕榈油作为膨化食品内的油脂,制备棕榈油基膨化食品,采用中心组合设计法探究挤压加工条件(水分含量、套筒温度、螺杆转速)对其品质(全氧化值)的影响规律,并确定实验条件下油脂氧化程度最低的各因素组合,且进行验证分析。研究表明,在挤压加工中,各因素对棕榈油基膨化食品的油脂品质的影响顺序为:水分含量﹥套筒温度﹥螺杆转速,其中水分含量与套筒温度之间具有显著的交互作用,当套筒温度较低(100~110℃)时,随水分含量增加,全氧化值逐渐减小,当套筒温度较高(110~160℃)时,随水分含量增大,全氧化值增大。实验条件下油脂氧化程度最低各因素组合为:套筒温度124℃,水分含量22%,螺杆转速250 r/min。在此条件下,预测值为27.15 meq/kg,通过此最优条件进行验证,实测值为(25.29±0.43)meq/kg。Abstract: The lipid quality of puffed food is easy to be changed during the extrusion processing,which affected quality of puffed food.As health and nutrition was concerned,palm oil was chosen to produce the palm oil- based puffed food,and the central composite design( CCD) was adopted to study the influence law of the extrusion processing conditions( moisture content,barrel temperature,screw speed) on its quality( total oxidation value),determining combined experimental conditions of the lowest oxidation content,and the verification test was carried out.The research showed that the order of factors influencing the oil quality of the palm oil- based puffed food during the extrusion processing was as follows: water content > barrel temperature > screw speed. A potential significant interaction between the moisture content and barrel temperature was shown,as when the barrel temperature was low( 100~110 ℃),the total oxidation value decreased with the increase of water content,when the barrel temperature was high( 110~160 ℃),the total oxidation value increased with the increase of water content. Within the scope of experimental conditions,combined various factors of the lowest oxidation content was obtained as the temperature of 124 ℃,the feed moisture of 22%,as well as the screw speed of 250 r / min.Under these conditions,the minimum total oxidation value was 27.15 meq / kg,and its experimental value was( 25.29 ± 0.43) meq / kg.