Research On Temperature Sensitive Control Release Film For Cantonese Bakery

Because bakery food is convenient, healthy, nutrient and delicious, which is closelyrelated with people’s eating habits and traditional culture, bakery food has been well receivedby consumers market. Traditional Cantonese bakery food has complex production process,high moisture and fat content, which easily causes lipid oxidation, mildew and sourpreservation issues. Preservatives are used mostly in food industry, but it increases thedifficulty of packaging with its high packaging costs, strict hygiene conditions, leakage andother issues. What’s more, bakery food produce close to neutral and at high temperatureconditions, it will cause unsatisfactory preservative, poor stability, high residual volume andsafety issues. In recent years, preservative agents and antibacterial materials are becomingresearch hotspots.In this paper, it screened wide spectrum of natural volatile preservative agent which wassuitable for bakery food, prepared temperature sensitive polyurethane using the phaseinversion, researched its temperature response behavior. And combined the preservativeagents with temperature sensitive polyurethane in order to prepare the temperature-sensitivecontrol release film, and were applied in bakery food. The main conclusions are as follows:(1) Assay the antimicrobial activity and screen the volatile natural preservative agents.Through measuring the inhibition zone of common microorganisms from Cantonese bakeryfood, it could be conclude that the root geraniol ketone D, cinnamic aldehyde and carvacrolhad better inhibitory effect on the tested compared with rosemary extract, caryophyllene andeucalyptol contrast. Furthermore, carvacrol and cinnamic aldehyde still had strong inhibitoryeffect and wild broad spectrum antimicrobial effect even under the condition of low dose.(2) Prepare the temperature sensitive polyurethane materials by two-step method andinvestigate its temperature response performance, permeability performance and micro-structure evaluation. Whether polyurethane has temperature sensitive is related to the ratio of reaction mass and the molecular weight of the PCL. And when the molar ratio of reactantswas1:1, The polyurethane with clear phase transition temperature could be obtained underthe condition of the molecular weight of PCL ranging from3000to8000. The phasetransition temperature of temperature-sensitive polyurethane was between45-55via DSCdetermination.(3) Combine the preservative agents with temperature sensitive polyurethane in order toprepare the temperature-sensitive control release film, and test their antimicrobial properties,release performance, and be applied to the Cantonese bakery food. Adding Carvacrol andcinnamaldehyde almost did not affect the temperature-sensitive polyurethane structure andtemperature response characteristics. Through the temperature-sensitive control releasepackaging for different Cantonese bakery products, it successfully extended product shelf life2-4times, and the sustained release rates were0.8-2.2%.(4) Analyze the kinetic for the release of temperature-sensitive control releaseantimicrobial package. It investigated thel concentration and the temperature had relevancewith the preservative agent diffusion from film. And the diffusion kinetics of films could bewell described by the first kinetic mode.