Chemical and Materials Engineering Department, University of Auckland, 20 Symonds Street, Auckland, 1142, New Zealand.
J Sci Food Agric. 2014 Apr;94(6):1149-53. doi: 10.1002/jsfa.6383. Epub 2013 Oct 13.
Aquacultured green lipped mussel (Perna canaliculus) is the New Zealand export leader of seafood in terms of weight. Different treatments shrink mussel meat differently and affect the consumer perception of half-shelled mussels. In order to quantify this, digital images of half-shelled green lipped mussels subjected to two postharvest treatments (ultrahigh pressure (UHP) and heat treatment (HT)) and raw controls were taken. The ratio of the view area of the meat to that of the shell (labelled as 'visual condition index' (VCI)) was measured using image analysis. A polygonal region of interest was defined on the image to depict the boundary of the meat and to calculate the view area.
Raw mussels had a VCI of 85%. HT mussels had a much reduced VCI of 41%, indicating shrinkage of the meat due to heat. UHP treatment used as a shucking method resulted in a VCI of 83%. Since VCI is one measure of quality for the consumer, this quantitative method can be used in the optimization of shucking treatment (HT or UHP).
VCI can be used to optimize postharvest treatments to minimize meat shrinkage. This method can also be applied to other shellfish such as oysters and clams.
在重量方面，水产养殖的绿唇贻贝（Perna canaliculus）是新西兰出口的海鲜主导品种。不同的处理方法会使贻贝肉收缩程度不同，从而影响消费者对半壳贻贝的感知。为了量化这一点，对经过两种产后处理（超高压（UHP）和热处理（HT））和未经处理的贻贝进行了数字图像拍摄。使用图像分析测量了壳内肉视图面积与壳视图面积的比例（标记为“视觉条件指数”（VCI））。在图像上定义了一个多边形感兴趣区域，以描绘肉的边界并计算视图面积。
未经处理的贻贝的 VCI 为 85%。HT 贻贝的 VCI 大大降低至 41%，表明由于热收缩导致肉收缩。用作去壳方法的 UHP 处理导致 VCI 为 83%。由于 VCI 是消费者质量的一种衡量标准，因此这种定量方法可用于优化去壳处理（HT 或 UHP）。
VCI 可用于优化产后处理以最小化肉收缩。该方法也可应用于其他贝类，如牡蛎和蛤。
