Hi and welcome to squidfish,
There is a fair bit of information on the FAO (FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS) website that might assist you (though some of it is a little old but still a good start). Here is an extract from the TORRY ADVISORY NOTE No. 77Handling and stowageSquid are not normally gutted at sea: they are simply washed and packed in ice. They are more susceptible to damage than gutted white fish if not handled carefully; crushing, scuffing or tearing of the skin, and burst ink sacs are indicative of rough handling. Squid are left ungutted because many markets, particularly overseas, prefer them whole; the ink and the tentacles are often used along with the flesh of the mantle when preparing squid for eating.Stowage in boxes is generally better than bulk stowage because there is less risk of crushing and bursting the ink sac. There should be at least 1 part of ice to 3 parts of squid by weight.Ungutted squid in ice keep in first class condition for up to8 days; after that time the flesh begins to redden, musty odours develop, and the squid become inedible in 13-14 days. Ungutted squid stowed in chilled seawater keep in first class condition for 6 days, and become inedible after 9days. The following scoring system can be used to assess the flavour of cooked squid after chilled storage of the raw material.
<TABLE> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">Score </TD> <TD colspan="1" rowspan="1" valign="TOP">Cooked flavour of squid </TD> <TD colspan="1" rowspan="1" valign="TOP">Days in ice </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">10 </TD> <TD colspan="1" rowspan="1" valign="TOP">fresh, characteristic of shellfish, sweet, meaty </TD> <TD colspan="1" rowspan="1" valign="TOP">0-1 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">9 </TD> <TD colspan="1" rowspan="1" valign="TOP">slight loss of freshness, creamy, sweet, meaty, metallic </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">8 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly sweet, slightly meaty, creamy, milky </TD> <TD colspan="1" rowspan="1" valign="TOP">6-8 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">7 </TD> <TD colspan="1" rowspan="1" valign="TOP">no sweetness, caramel </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">6 </TD> <TD colspan="1" rowspan="1" valign="TOP">neutral </TD> <TD colspan="1" rowspan="1" valign="TOP">8-10 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">5 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly sour </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">4 </TD> <TD colspan="1" rowspan="1" valign="TOP">sour, musty, cabbage </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">3 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly bitter, overripe cheese, oily, slightsulphide </TD> <TD colspan="1" rowspan="1" valign="TOP">13-14 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">2 </TD> <TD colspan="1" rowspan="1" valign="TOP">bitter, sulphide </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">1 </TD> <TD colspan="1" rowspan="1" valign="TOP">strongly bitter, putrid </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> </TABLE> <A name="Processing"></A> ProcessingWhole squid can be distributed chilled in ice or frozen. Squid for freezing should be of good quality, less than 7 days in ice and free from damage. They should be packed in cartons and frozen quickly. An air blast freezer is suitable; the cartons should be left open during freezing to keep freezing time short. Whole squid keep in good condition in cold storage at -30ðC for 9 months or more. More detailed information on the freezing and cold storage of fish is given in Advisory Notes 27 and 28.The edible parts of squid are prepared in the following manner. The whole squid is washed, and the tentacles are cut off just in front of the eyes; these are retained, since they can be eaten once the suckers have been removed. The head is twisted and the mantle is squeezed whilst the head,pen and guts arc gently pulled out. The mantle can be left whole, with the gut cavity washed out, or it can be split and opened so that any remaining guts can be scraped or washed away.The skin on the mantle can be peeled or scraped off; blanching in hot water at 25-30ðC for about 15 seconds makes the skin easier to remove. Machinery for heading, gutting, skinning and cutting squid is available.
There is a fair bit of information on the FAO (FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS) website that might assist you (though some of it is a little old but still a good start). Here is an extract from the TORRY ADVISORY NOTE No. 77Handling and stowageSquid are not normally gutted at sea: they are simply washed and packed in ice. They are more susceptible to damage than gutted white fish if not handled carefully; crushing, scuffing or tearing of the skin, and burst ink sacs are indicative of rough handling. Squid are left ungutted because many markets, particularly overseas, prefer them whole; the ink and the tentacles are often used along with the flesh of the mantle when preparing squid for eating.Stowage in boxes is generally better than bulk stowage because there is less risk of crushing and bursting the ink sac. There should be at least 1 part of ice to 3 parts of squid by weight.Ungutted squid in ice keep in first class condition for up to8 days; after that time the flesh begins to redden, musty odours develop, and the squid become inedible in 13-14 days. Ungutted squid stowed in chilled seawater keep in first class condition for 6 days, and become inedible after 9days. The following scoring system can be used to assess the flavour of cooked squid after chilled storage of the raw material.
<TABLE> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">Score </TD> <TD colspan="1" rowspan="1" valign="TOP">Cooked flavour of squid </TD> <TD colspan="1" rowspan="1" valign="TOP">Days in ice </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">10 </TD> <TD colspan="1" rowspan="1" valign="TOP">fresh, characteristic of shellfish, sweet, meaty </TD> <TD colspan="1" rowspan="1" valign="TOP">0-1 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">9 </TD> <TD colspan="1" rowspan="1" valign="TOP">slight loss of freshness, creamy, sweet, meaty, metallic </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">8 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly sweet, slightly meaty, creamy, milky </TD> <TD colspan="1" rowspan="1" valign="TOP">6-8 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">7 </TD> <TD colspan="1" rowspan="1" valign="TOP">no sweetness, caramel </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">6 </TD> <TD colspan="1" rowspan="1" valign="TOP">neutral </TD> <TD colspan="1" rowspan="1" valign="TOP">8-10 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">5 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly sour </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">4 </TD> <TD colspan="1" rowspan="1" valign="TOP">sour, musty, cabbage </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">3 </TD> <TD colspan="1" rowspan="1" valign="TOP">slightly bitter, overripe cheese, oily, slightsulphide </TD> <TD colspan="1" rowspan="1" valign="TOP">13-14 </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">2 </TD> <TD colspan="1" rowspan="1" valign="TOP">bitter, sulphide </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> <TR valign="TOP"> <TD colspan="1" rowspan="1" valign="TOP">1 </TD> <TD colspan="1" rowspan="1" valign="TOP">strongly bitter, putrid </TD> <TD colspan="1" rowspan="1" valign="TOP"> </TD> </TR> </TABLE> <A name="Processing"></A> ProcessingWhole squid can be distributed chilled in ice or frozen. Squid for freezing should be of good quality, less than 7 days in ice and free from damage. They should be packed in cartons and frozen quickly. An air blast freezer is suitable; the cartons should be left open during freezing to keep freezing time short. Whole squid keep in good condition in cold storage at -30ðC for 9 months or more. More detailed information on the freezing and cold storage of fish is given in Advisory Notes 27 and 28.The edible parts of squid are prepared in the following manner. The whole squid is washed, and the tentacles are cut off just in front of the eyes; these are retained, since they can be eaten once the suckers have been removed. The head is twisted and the mantle is squeezed whilst the head,pen and guts arc gently pulled out. The mantle can be left whole, with the gut cavity washed out, or it can be split and opened so that any remaining guts can be scraped or washed away.The skin on the mantle can be peeled or scraped off; blanching in hot water at 25-30ðC for about 15 seconds makes the skin easier to remove. Machinery for heading, gutting, skinning and cutting squid is available.