Investigation On The Technology And Aeration Mechanism Of Whipped Topping

The formula and processing conditions of whipped topping were optimized. The microstructure of whipped topping foam was photographed through dye-LM and ESEM. Partial coalescence and whipping stages were discussed.Through single factor experiments and two-level design, three factors: sodium caseinate, hydrogenated vegetable oil and Span60 were determined as the main factors. Then through RSA (response surface analysis) method, the optimized formula consisted of: hydrogenated palm kernel oil and coconut oil (3:1) 25.1%;sodium caseinate 2.05%;sugar 8.0%; NaCl 0.5%;xanthan gum 0.1%;guar gum 0.1%; macrocrystalline cellulose(MCC) 0.3%; KH2PO4 0.1%;Tween60 0.15%;Span60 0.43%;lecithin 0.3%;sodium stearyl lactate(SSL) 0.2%;propylence glycol ester of fatty acids(PGA) 0.2%.The processing conditions included: heated at 60℃ for 3 hours, homogenized at 14Mpa, sterilized at 75 ℃ for 15 minutes, chilled in ice water bath, aged at 4癈 for 24 hours and frozen at -18℃. Whipped at 4℃ and 250rpm, the whipped topping's overrun could be 332%. The stiffness could keep stable for 72 hours at 4 ℃.The process of partial coalescence, which contributes to the whipped topping structure significantly, was as follows. Firstly, with the participation of emulsifiers, small fat globules contact and aggregate into bigger ones, fat crystals are formed at the same time. Secondly, under the shear of whipping, two fat globules crush into each other and the MFGM between them is punctured by fat crystals, the liquid fat flows and wets crystals making two fat globules melded. Thirdly, more and more fat crystals coalesce to form a firm network; the free fat increases greatly.The process of whipping was divided into four stages. At the first stage, big bubbles break into little ones; the overrun increases rapidly; whipped topping behaves like fluid and the leakage is 100%; only a few fat globules coalesce into small aggregates. At the second stage, leakage declines rapidly; the viscosity of foams increases; more and more proteins are replaced by partial coalesced fat, this is the effective whipping stage. At the third stage, overrun and foam viscosity increase slowly; the maximum overrun and viscosity are reached; partial coalesced fat forms a stable structure. At the last stage, the overrun and viscosity begin to decline caused giant fat aggregates to form.Changes in key structure-forming components and rheological properties during the four whipping stages were analyzed. The bubble size reaches maximumat the first stage, then decreases gradually and becomes stable at the last stage. The overrun rises rapidly until it reaches maximum at the third stage, at the fourth stage it decreases a little. The level of free fat increases with fat partial coalescence. Viscosity increases significantly at the first two stages, it becomes stable at the third stage, after that it decreases. Elasticity increases at all stages.