ABSTRACT
In this study, the effect of chitosan coating containing emulsion and nanoemulsion of Hyssopus officinalis essential oil (EO) on the chemical, microbiological and sensory characteristics of shrimp (Litopenaeus vannamei) was investigated. The minimum value of TVB-N (Total volatile basic nitrogen), TBARS (Thiobarbituric acid reactive substances), PV (peroxide value), TMA-N (Trimethylamine-nitrogen) and FFA (Free fatty acids) after 12 days were shown in NE + HEO 1% (coating containing chitosan with nanoemulsion of EO) with 20.53 mg N/100 g, 0.5 µg/kg, 0.88 MAQ peroxide/kg, 1.3 mg/100 g and 12.16 mg 100% of oleic acid, respectively. Also, minimum value of pH after 12 days was related to the CE + HEO 1% (coating containing chitosan with emulsion of EO) with 7.60. The minimum value of psychrophilic and mesophilic microbial count after 12 days were shown in NE + HEO 1%, 4.40 ± 0.36 and 4.03 ± 0.06 cfu/g, respectively. The best score of sensory evaluation was observed in the NE-HEO 1% treatment. As a result, the edible coating containing chitosan-based nanoemulsion could be effective to the preservation of shrimp's microbiological, chemical, and sensory characteristics.
ABSTRACT
Nowadays, the consumption of meat and meat products has been increased with modern manufacturing techniques. Due to the economic value, the likelihood of using unauthorized tissue is possible in meat products. The aim of this study was to apply morphological methods for detection of unauthorized tissues in meat sausage. In this study, a total number of 20 samples of different types of sausages were randomly collected from markets, in north-east of Iran. Each sample was divided into three equal parts and three paraffin-embedded blocks were prepared from each part (180 blocks). Then the sections were stained using Hematoxylin and Eosin, Masson's trichrome, Periodic acid- Schiff/Alcian blue and Verhoeffe/Van Gieson. A total number of 720 slides were observed using a light microscope. This research showed the use of unauthorized tissues in the sausages which was detected by histological methods. We observed authorized tissues like skeletal muscle fiber (100%), fat tissue (100%) and plant material (97.70%). A wide range of unauthorized tissues were detected including dense connective tissue (6.66%), cartilage (28.30%), bone (8.30%), skin (51.60%), smooth muscle (1.66%) and blood vessels (11.66%). The results of this study confirmed the use of unauthorized tissue in meat sausages in Iran and concluded that the histological methods especially Masson's trichrome staining are a practical technique for routine assessment of authenticity and quality of sausage to protect the consumers from adulteration.
