| Because in the enterprises of squid processing only squid carcasses are used for aquatic products processing,squid foot(ear)and skin,etc are not used very well,causing resource waste.Thus,in this thesis Argentina squid foot was used to prepare fried snack food,the fried processing techniques on the squid foot quality characteristics,the mechanism of color change were studied.The study can provide certain theoretical basis for the snack food.The results are showed as follow:(1)The effect of different frying temperature and time on squid foot quality was studied.Results show that with the longer fried time,L* and b* values of fried squid food gradually declined,a* value increased gradually(p<0.05),the higher the frying temperature,the greater changes of L*,a* and b* values,and hardness,chewiness and shear force.The elasticity and cohesiveness change of squid is not obvious.TBA and TVB-N values rose gradually under the higher of fried temperature.The squid food fried at 135℃ for 3 min showed better sensory evaluation values on the color,smell,texture and comprehensive evaluation of general acceptance.(2)The moisture distribution,quality characteristics and color change mechanism of fried squid foot in the fried process were studied on the squid with the skin(A),peeling squid(B)and squid skin(C).Results show that the L*,a*,b* and total aberrations delta E of sample B were higher than that of A and C groups(p<0.05).The reducing sugar content of all samples decreased with prolonged frying time,and group B showed a higher reducing sugar content than A and C.Total free amino acid content of fried squid decreased from 2970.36 fresh samples to 2955.25 mg/100g(dry base),the content of arginine changed significantly as compared with the fresh sample.There might present Maillard reaction due to the same decrease of reducing sugar content amino acids(especially arginine)which might be part of reason for the color changes.Low field nuclear magnetic resonance result showed that with prolonging offrying time,the T2 relaxation time,especially the T22 decreased rapidly,and the decline range of B group was significantly higher than A group.There was no significant difference between the TVB-N value and TBA value between the A group and the B group(p>0.05),and a significant difference between group C with group A and B was found(p<0.05).(3)The changes of fatty acids,free amino acids and volatile flavor compounds in fried squid product were studied.The results showed that the fatty acid content of squid foot was higher with EPA C20:5(5.11%),C22:5(14.07%),DHA C22:6(30.95%),and the content of EPA was much higher than that of DHA,the total mass fraction of DHA and EPA was 36.06%.The fatty acid composition of fried squid was significantly changed before and after frying,the relative content of SFA and MUFA in squid meat fat and PUFA respectively by 13.62%,3.85%ande 52.72% before fried to 25.04%,19.12% and48.40% after fried.Contents of total free amino acid and essential amino acid in fresh samples were 2970.36 and 383.85 mg/100 g,respectively,which had the highest cysteine content,1205.55 mg/100 g,followed by arginine 785.18 mg/100 g.The total of free amino acid content decreased slightly after curing,frying and hot air drying,but there was no significant change(p>0.05).(4)The quality changes of Fried squid foot stored at 25℃and 50℃were studied.Color,TBA,TVB-N,POV,the formaldehyde and the total bacterial count of fried squid foot were observed during storage.The results indicated that in the two kinds of storage temperature,with the increasing of storage time,L* and b* value decreased,a* value increased gradually;TBA,TVB-N,POV and the total number of colonies were gradually decreased.The quality characteristics of fried squid foot at 25℃were significantly higher than 50℃. |
PDF Full Text Request