LV14785B - Method for producing smoked fish - Google Patents

Abstract

Invention relates to food industry, particularly to methods for producing smoked fish products from fresh or frozen Baltic sprats or Baltic pilchards. The offered method contains several stages. At first the frozen fish are defrosted at a temperature of 12 to 18 centigrade. The frozen fish after defrosting or the fresh fish are rinsed in flowing water and thereafter these are brought to smoking.The hot-smoking process is carried out in three zones: drying area, smoking area and cooling area, and mixture of hot air, steam and smoke-fume are fed to fish in container as well from top-side as from bottom-side (Fig.4; Fig.6).The resulting smoked fish products are obtained characterized by low-grade content of benzo[a]pyrene (1.7±0,3 µg/kg), that is lower as allowed level 5 µg/kg according to European Commission Regulation No. 1881/2006. Healthy preserved food of high quality could be produced using fish that are smoked in such way.

Description

DESCRIPTION OF THE INVENTION

The technique relates to the food industry and involves improving food and developing new techniques for obtaining it. This technique can be used to make hot smoked fish and sterilized canned fish from hot smoked Baltic sprat or Baltic herring. The invention relates to the production of products such as "Sprats in oil", "Riga sprats in oil", "Sprats in oil", "Sprats in jelly", "Sprats in tomato sauce", "Smoked herring in oil" and "Sprats in paste".

There are several patented methods of smoking fish, for example, patent No. 1659 "Sprat Canning Method", registered in Latvia, which uses only alder wood smoke for fish smoking. The fish is smoked in three stages: the fish is dried at 40 to 60 ° C for 15 to 30 minutes, boiled in hot steam at 90 to 140 ° C and smoked at 80 to 120 ° C. Cooking and smoking time is 1 to 1.5 hours.

Commonly known fish processing technology for the preparation of smoked fish in a smokehouse ΤΚΥ-Ι - a two-tunnel conveyor-type smokehouse with a smoke generator and a smoke inlet from above (Fig.l.) manufactured by AS «Miiduranna Texas» (Estonia), Contains hot steam treatment, low smoke smoking, and smoke from above. It gives the product an uneven color and causes tar drops and runoff on fish when smoked. The upper frames are dried, but the lower frames retain high levels of moisture. The level of benzo (a) pyrene in fish reaches the critical level of 5 pg / kg as laid down in European Regulation (EC) No 1881/2006 and may even be exceeded.

The two-tunnel smoking furnace ΤΚΥ-1 is shown in Fig. 1, but Fig. 2. Figure 3 is an end view of said smoking tunnel and Figure 3 is a cross-section along axes A-A and B-B. The unit contains the following elements:

- smoke exhaust fan,

- flue gas flow through tunnel,

- conveyor rail for smokers,

- smoking rabbit,

- smoking tunnel,

- control valves.

The object of our invention is:

(1) to produce a low benzo (a) pyrene product;

2) to provide a uniform coloring of all fish in one container,

3) avoid over-drying of fish in the upper frames,

4) reduce the moisture content of the fish in the lower frames,

(5) to prevent the formation of smokescreen droplets or run-off on fish,

6) to provide a safe and durable product quality, while maintaining the traditional smoking method using only alder wood smoke (using alder wood chips as fuel).

According to our invention, the smoking method is as follows. Fresh or frozen Baltic herring or Baltic herring of various sizes are used for canning. Frozen fish are thawed in a dedicated installation at a temperature of 12 to 18 ° C. After thawing, the frozen fish or fresh fish are rinsed in running water and exposed through the eyes to sharpened partridges. The fish are further smoked.

The modified smoking furnace according to the invention is shown in Fig. 4, Fig. 5. and Fig.6. (Fig. 6 - cross-sectional view along the A-A and B-B chimney axes), respectively, the structure is supplemented with iron pipes (150x200 mm), which pass to the outside of the tunnel and are marked with 7.

Hot smoking takes place in a smoking tunnel ΤΚΥ-Ι - a two-tunnel conveyor-type smoking oven with a smoke generator with a smoke inlet from above, which in its design passes through a mix of pipes from the smoke generator to mix hot air, steam and smoke. The mixture is further introduced into the drying and smoking area from below (according to the original design, the mixture of smoke, steam and hot air was introduced only from above). The smoking containers (drums) with the fish are moved at regular intervals with the chain conveyor in the tunnel one step at a time (Fig.2).

The drying process takes up to 20 minutes in the drying area. at a temperature of 40 to 60 ° C and treatment with hot air, steam and smoke mixture lasts up to 25 min. at temperatures between 100 and 140 ° C. The hot air, steam and smoke mixture is fed from both the top and bottom simultaneously, with the possibility of proportionally changing the flow rate of the mixture from above via the control valves (position 6 in all drawings).

In the smoking area, treatment with a mixture of hot air, steam and smoke lasts for up to 40 minutes at a temperature of 100 to 120 ° C. The hot air, steam and smoke mixture is also fed from both the top and bottom, with the ability to proportionally change the flow rate of the mixture from above via regulating valves. The percentage of hot air, steam, and smoke mixture feed rates can be changed from 10% to 90%.

The processes in the drying and smoking areas take a total of 45 minutes to 1.5 hours, depending on the species and size of the fish.

In the cooling zone, the smoked fish are chilled at a temperature of between 20 and 30 ° C.

The fish containers (drums) are then removed from the smoking tunnel for further production of canned fish.

Samples for analysis are taken from the finished product.

The results of the benzo (a) pyrene analyzes carried out on the dates indicated are as follows (analyzed by the Scientific Institute for Food Safety, Animal Health and the Environment "BIOR"):

1) with a conventional smoking structure

05/12/2011 - 3.4 ± 0.6 pg / kg

05/26/2018-5.5 ± 1.0 pg / kg

2) with redesigned structure (connected pipes for supply of hot air, steam and smoke mixture from below)

10/17/2011, -1.3 ± 0.3 pg / kg

12/5/2011 - 1.7 ± 0.3 pg / kg

Claims (3)

Claims 1. The method of preparing smoked fish using fresh or frozen Baltic sprat or herring differs in that the method of feeding the hot air, steam and smoke mixture in the smoking tunnel, i.e. said mixture being introduced from both the top and the bottom simultaneously. Process for preparing smoked fish according to claim 1, characterized in that the amount of hot air, steam and smoke mixture can be changed from above and below by means of control valves depending on the species (herring or sprat) of the smoked fish, whether the fish is fresh or frozen. The method of preparing smoked fish according to claim 2, wherein the amount of hot air, steam and smoke mixture can be varied from 10% to 90%.