| The paper aimed to study the retort pouch packed roast chicken wings of high qualityand chewiness. This paper studied the drying rule, quality change rule and optimization ofbroiler chicken wings during roasting; the drying rule and optimization during intermittentmicrowave; then the effects of moisture content and lethality value on the heat penetration andquality of retort pouch packed roast chicken wings.(1) The present study investigated the influence of air temperature on the drying kineticsof broiler chicken wings and quality of end product during convective dehydration at60,70,80,90and100℃. The results showed that the drying occurred throughout under falling rateof drying period and the predominant mechanism of mass transfer in the sample is that ofinternal mass transfer. The change of moisture content and drying rate had significant changeat different hot air temperatures and the drying rate increased with the increasing oftemperature. The effective moisture diffusivity increased with increase of air temperature, andthe valve of Deffwas between3.09~11.1310-9m2/sfrom60to100℃, the activation energyof which was33.08kJ/mol. Eight different empirical drying models were compares and basedon statistical tests results, the page model gave the best fits. The result of quality analysis ofend product showed that hardness, chewiness and shear force, the value of which had themaximum value under the drying temperature of90℃, had significant change at different airtemperatures, while the value of springiness, cohesiveness and resilience had no significantchange; The TBA index and acid value depended during drying more on exposure time thanon temperature. The value of k and n of Page model were significantly correlated with Deff,and hardness and shear force were significantly correlated with chewiness.(2) In order to produce roasted broiler chicken wings of high quality and chewiness,combination of hot air drying and roast at high temperatures were used to get a kind ofready-to-eat snack food, whose optimum processing parameters were obtained by responsesurface methodology (RSM). The effects of hot air drying temperature (80~100℃), middlemoisture content (40~50%) and roasted temperature (150~200℃) on chewiness, shear forceand Sulfo-Barbitone Acid (TBA) value were studied. Data were standardized by queuinganalysis and entropy weight method was applied to get weight coefficients of each index and the final comprehensive score of multi-index system. The results showed that as hot airtemperature and middle moisture content raised, chewiness and shear force increased and thenfell. However chewiness decreased with the raise of middle moisture content. The effects ofmiddle moisture content and roasted temperature were more significant than hot air dryingtemperature. In addition, interaction effect of middle moisture content and roastedtemperature on chewiness and shear force was significant.Weight coefficients of hot airtemperature, middle moisture content and roasted temperature was0.270,0.412and0.315respectively by entropy weight method. Box-Behnken design was applied to confirm theoptimum experiment condition. Design expert analysis indicated that the best hot air dryingtemperature, middle moisture content and roasted temperature were90℃,43%and170℃respectively. Under these conditions, the quality indexes of roasted chicken wings werechewiness of14.42kg, shear force of8.10kg, TBA value of0.623mg/kg and comprehensivescore of of8.26on average with a1.08%relative error comparing with the predicted value ofmodel.(3) The study investigated the quality change of roasted broiler chicken wings duringroasting under the optimized parameters, and analyzed the sensory quality of roasted endproduct (REP) and2kinds of market products (SH1、SH2). The result showed that awvalue ofwings decreased by9.3%during roasting, while the TBA value increased. The accumulationof TBA value during drying period was3.92times the amount of the roasting period. Theindex of color (L*, a*, b*) increased and then fell during roasting; The value of hardness,chewiness and shear force increased by9.8times,13.72times, and3.15times after roasting,respectively. The drying period was the main process of dehydration and texture improvement.Compared with market products, the moisture and salt content, L*and a*value of REP werewithin the range of market products, while the TBA value of REP was the lowest. The valueof hardness, chewiness and shear force were also within the range of market products. Thesensory evaluation showed REP and SH1, which had the suitable dryness and chewiness, hadthe best overall taste and highest acceptance. So the suitable moisture content of roastedchicken wings should be over30%.(4) The present study investigated the influence of microwave power density (3.31、4.43、5.59W/g) and pulse ratio (PR=1、2、3) on the drying kinetics and quality of broiler chicken wings. The result showed that the drying occurred throughout under constant rate ofdrying period. The change of moisture content and drying rate had significant change atdifferent microwave conditions. The effective moisture diffusivity had significant change atdifferent microwave conditions. The value of Deffwas between2.71~0.84×10-7m2/s at thecondition of η=3.31W·g-1/PR=1~3; between3.51~1.1×10-7m2/s at the condition ofη=4.43W·g-1/PR=1~3; between4.44~1.35×10-7m2/s at the condition of η=5.59W·g-1/PR=1~3.Eight different empirical drying models were compared and based on statistical tests results,the Page model gave the best fits. The calculated specific energy consumption ranged from13.48to17.97MJ/kg under different microwave condition, and the specific energyconsumption depended more on pulse ratio than on power density. The principal componentanalysis was used to investigate9groups of microwave conditions. Four principalcomponents were extracted, and the cumulative variance contribution was83.2%. Thecomprehensive score ranking of principal component showed that top3of microwavecondition was3.31W·g-1/PR=3、5.59W·g-1/PR=2and4.43W·g-1/PR=2.(5) The heat penetration characteristics and kinetics of reactions leading to qualitychanges in roasted broiler chicken wings with different moisture content (30~40%) sterilizedto different lethality value (0~5min) at121℃were studied. The results showed that the lagfactor of heating and cooling (jh, jcvalue), the heating and cooling rate index (fh, fcvalue)decreased with the decreasing of moisture content. The lower moisture content sample couldreach a higher lethality value at the same process time. The water activity had significantchange at different moisture content, while had not at different lethality value. The curves ofcolor changes (L*, b*,△E) obeyed zero-order kinetic equation. The reaction rate of color wassignificantly influenced by moisture content; with the decrease of moisture content, thereaction rate of L*value increased while the reaction rate of b*and△E value decreased. Thecurves of TBA value obeyed zero-order kinetic equation and its reaction rate increased withthe decrease of moisture content. Specially, low lethality value of sterilization could improvethe hardness, chewiness and shear force, the decreasing phase of which was modeled using afirst-order kinetic equation, respectively. And the reaction rate of damage of hardness,chewiness and shear force decreased with the decreasing of moisture content. The value ofhardness was positively correlated with chewiness and shear force. TBA value was positively correlated with△E and b*.△E was negatively correlated with L*, while positively correlatedwith b*. Interaction analysis showed that the interaction effect of moisture content andlethality value had significant effect on hardness, chewiness,△E and b*. |
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