Lobster quality indicators for grading

AbstractMale lobsters (Homarus americanus) harvested as ‘quarters’ (1.25 lbs/567 g) in two time periods (winter, N = 16, and summer, N = 25) of 2018 are examined. Indicators of quality data were collected for each lobster, including non‐invasive measures (shell hardness, carapace length, sex, live weight, colour, body shape, location, time of harvest) and invasive measures (blood protein [BRIX] level at time of harvest, cooked weight, meat content). Lobster BRIX levels are used as a proxy for actual meat content and as the key indicator of lobster quality. A regression model of the relationship between the natural logarithmic transformation of lobster BRIX levels (independent variable) and meat content yield as a percentage of shell‐on (uncooked) weight (dependent variable) is presented. The objective of this study is to evaluate alternative BRIX‐based decision rules for achieving desired meat content percentage yields for preparing shipments to global markets. The present study found that BRIX‐based grading rules can be determined to achieve minimum desired meat yields, minimum overall shipment yields and minimum proportions of shipments below desirable yield rate. For a minimum desired industry threshold of 24% meat content, the preferred BRIX value rules are (i) 8.5 mg mL−1 and (ii) ‘9 mg mL−1 with 10% plus condition’. These rules improve the admissibility of samples and reduce the risk of below desirable meat yields.