ABSTRACT
The influence of different addition levels (0.1% to 0.5%) of thermo-reversible curdlan gels (TRC) and thermo-irreversible curdlan gels (TIRC) on the physicochemical and textural characteristics of frankfurters, as well as dynamic rheological properties of meat batters, was investigated. Increased percentages of TRC and TIRC were associated with lower cooking loss and quicker relaxation times, as well as superior emulsion stability, and higher L* -values and b* -values of frankfurters (P < 0.05). Moreover, with equal curdlan concentrations from 0.3% to 0.5%, TRC showed higher hardness and chewiness values than those with added TIRC (P < 0.05), but the gumminess, springiness, and resilience values were almost the same between each treatment (P > 0.05). The textural profile results were in strong agreement with the rheological data. Principal component analysis revealed that certain quality attributes were affected differently by the inclusion levels of TRC and TIRC. Additionally, the distinctive mechanism of the formation of the complex meat protein network by TRC or TIRC was also clarified and verified via scanning electron microscopy analysis. Further studies will investigate the molecular interactions of meat proteins with these two types of curdlan gels as a function of addition levels. PRACTICAL APPLICATION: Curdlan can form two different types of gels mainly depending on heating temperature, designated as thermo-reversible curdlan gels (TRC) and thermo-irreversible curdlan gels (TIRC), respectively. The addition of these two gels could improve the textural and gel properties of frankfurters, as well as improve the rheological profiles of meat batters. Each gel type invokes a different mechanism of influence on the formation of the complex meat protein network. Results indicate that TRC (mainly as an effective gelling agent) and TIRC (mainly as a potential fat-mimetic) can provide distinctive frankfurter formulations catered to the requirements preferred by different consumers.
Subject(s)
Gels/chemistry , Meat Products/analysis , beta-Glucans/chemistry , Cooking , Emulsions , RheologyABSTRACT
OBJECTIVE: To verify houseflies Musca spp. as the intermediate host of Thelazia callipaeda and reveal epidemiological situation of thelaziasis in Hubei province. METHODS: Dogs eyes infected with T. callipaeda, 400 houseflies Musca and 259 fruitflies Amiota okadai in the city of Laohekou city (previously named as Guanghua county) of Hubei province had been investigated since September 2000. The newborn larvae of T. callipaeda from Laohekou suburbs were fed to houseflies Musca and A. okadai. Larvae used for the study were isolated from female T. callipaeda in laboratory and the susceptibility to houseflies Musca and A. okadai was observed. RESULTS: Twenty-one dogs from Laohekou, the original epidemic areas of thelaziasis were examined and 7 positive dogs in 21 (33.3%) and 11 T. callipaeda (9 females and 2 males) were identified. From 1975 to 2000, no thelaziasis cases were found through retrospective surveys. These 200 houseflies Musca and 135 A. okadai were dissected for examination but showed all negative with the infection. However, newborn larvae of T. callipaeda were used to experimentally infect 112 houseflies Musca and 84 A. okadai and all infected flies were examined on the 20th day after inoculation. As a consequence, houseflies Musca failed to be infected but 9 in 84 (10.7%) A. okadai were positive. 26 infective larvae of T. callipaeda were obtained and 21 of them were inoculated into right eye of one rabbit. The female worm began to produce newborn larvae in 37 days after infection and 3 adult T. callipaeda (two females and one male) were obtained. CONCLUSIONS: Fruitflies A. okadai from Hubei province were susceptible to T. callipaeda, which was similar to the result of experimental studies in Anhui province. This survey further confirmed that A. okadai was the intermediate host of T. callipaeda but not houseflies Musca. Infective resources (adult dogs, for instance) had been under controlled thus human thelaziasis had been eradicated in this rural area.
