Secret of Beef Jerky

May 03, 2018

Secret of Beef Jerky

Beef jerky is a form of dried meat that was firstly prepared by Natives Americans custom for their nomadic lifestyle. The cowboy adopted this type of food as they could store in the saddlebag. The word ‘jerky’ is derived from the Quechua word ch’arki which means “dried salted meat”. From the word jerky itself, it shows that the meat has been cut into long strips and dried. The cowboys hand cut or pull (jerked) meat from a side of beef. Beef jerky is produced from very lean muscle tissue from the hind leg such as topside meat or inside or outside rounds. No connective tissue or fat should present in the meat and as a result the product is low in fat content.

For the production beef jerky, the meat should be extremely well-trimmed and sliced into a slice of 4 – 8 mm thick. The slices of meats are weighed and subsequently mixed with marinade containing salt, nitrite, ascorbate (erythorbate), sugar, spices (garlic, anion, chili, cayenne pepper) and commonly red wine, soy sauce or Worcestershire sauce are added as well. Some places used other recipes of marinade according to consumers preferences. The similarity in the production of beef jerky is the used of salt to reduce water activity inside the meat slices. Reducing water activity can prevent microbial growth and the beef jerky shelf life can be extended to months without refrigeration.

The beef jerky is left to marinade for 12-14 hours under chilled conditions to make sure the marinade is absorbed into the meat. In the marinade that contain nitrite, sodium nitrite is commonly used. This nitrite is the vital ingredient for meat curing. Nitrate may be used with the aim of producing nitrite from it by microbiological reduction. Nitrite reacts with myoglobin to produce the colour characteristic of cured meat. The antimicrobial activity of nitrite is a well-known property. It was established already in early 1950’s that nitrite afforded specific protection against outgrowth of spores of Clostridium botulinum. The salt in the marinade is used an effective inhibitor of microorganisms and to impart flavour. Different organisms have specific, varying tolerance to salt, and in general, salt can decrease the availability of water. After marinade is done, the beef jerky is placed on grid racks or hung up for the drying process. There are several methods of drying can be done to make sure that the drying process is sufficient to increase shelf life and retain the flavour of the meat.

One of the methods is to dry the meat at 60 – 65 °C and at low relative humidity until an A_w below 0.89 is obtained, with no smoking take place. Another method is to dry the laid marinated slices of meat and smoke them at 60 – 70 °C until the desired smoke intensity is obtained. Further drying then take place at the same temperature until an A_w below 0.89 is obtained. The other method that can be done is to apply smoke heat right from the beginning at 60 – 70 °C until an A_w to be low as 0.89 obtained, which result in a strongly smoked product. The marinated meat is also first heated with dry heat to 70 °C to kill pathogens before subsequent drying to reduce the A_w level to around 0.86. At an A_w below 0.89, bacteria such as Enterobacteriaceae, as well as Staphylococcus aereus are well controlled. An A_w of less than 0.86 is aimed for so that the product is safe from microbial spoilage and shelf-stable without the need for refrigeration.
Smoke for meat is normally generated by slow combustion of hardwood sawdust. Smoking is done for flavour and appearance as well as for preservative and antioxidant effects. The phenols produced from the smoke play an important role that can provide a degree of bacteriostatic action. Drying the meat using smoke is mainly to reduce the water activity of the slices meat. The meat can be easily smoke as the high surface area of the meat that exposed to the heat and smoke. So, the relative humidity is easily reduced. The moisture level of the sliced meat is also decreased.

In conclusion, what’s used to be the nomadic technology of preserving and consuming meat has become another high protein option of snacking . Close analysis of the processing technology reveals the application of hurdle technology that involves different preservation factors including temperature, water activity, and chemical compounds as preservatives, in addition to its thin structure of the meat.

These are two videos that show the process of making beef jerky at home and also the processing at the factory: