UNIT 4: SALTING, CURING, AND SMOKING

Salt

inhibits most spoilage by reducing the amount of water available for microbial growth.

Egyptians

were the first to realize the preservation possibilities of salt .

Sodium

draws the bacteria -causing moisture out of foods, drying them and making it possible to store meat without refrigeration for extended periods of time .

Mesopotamians (3000 BCE)

They generally used salt to preserve meat and fish. Early Roman writers such as Cato (234-149 B.C.E.) clearly explained the need to salt perishable meats and vegetables to preserve them.

Xiechi Lake

• Also called Yuncheng Salt Lake

• The largest natural lake in Shanxi in Northern China.

• It is a saline lake used for production of salt

Salt

• A crystalline mineral made of two elements, sodium (Na) and chlorine (Cl).

• Most of the world’s salt is harvested from salt mines or by evaporating seawater and other mineral-rich waters.

Refined Salt

• Most common type of salt

• Highly refined

• Clump – anti-caking agents

• sodium chloride — 97% or higher

• Added iodine

Sea Salt

• evaporating seawater

• Coarse, less ground

• Mostly just sodium chloride + trace minerals like potassium, zinc, and iron

• Microplastics

Darker sea salt

higher concentration impurities and trace nutrients

Himalayan Salt

• Mined in Pakistan

• Khewra Salt Mine

• Iron oxide (rust)

• Slightly lower in sodium than regular table salt

Kosher Salt

• A naturally occurring mineral that is coarse-grained

• Historically used for removing surface blood from meats

• Large flake structure/size

• Not ideal for baking

• Different brands vary

Celtic Salt

• Type of sea salt (France)

• Grayish color and contains a bit of water, which makes it quite moist

• Lower in sodium than plain table salt (trace amounts of minerals)

• While this contains more minerals than table salt, these are in trace amounts, and it still contains a high percentage of sodium chloride.

Sea salt

• produced through evaporation of ocean water or water from saltwater lakes, usually with little processing

• Depending on the water source, this leaves behind certain trace minerals and elements

• The minerals add flavor and color to this salt, which also comes in a variety of coarseness levels .

• typically mined from underground salt deposits .

• this salt is more heavily processed to eliminate minerals and usually contains an additive to prevent clumping.

• also has added iodine, an essential nutrient that helps maintain a healthy thyroid.

Salting

the process of preserving food by applying dry salt or a brine (saltwater solution) to inhibit bacterial growth.

Osmosis

Salt draws out moisture from the food and microbes through _____, creating an environment that prevents spoilage and pathogen growth.

Pink Salt

• Added to tocino to prevent meat from spoiling

• A curing agent that imparts that unique, smoky, flavor, and the desirable pink color.

Curing

• the addition to meats of some combination of salt, sugar, nitrite and/or nitrate for the purpose of preservation, flavor and color.

• The cure ingredients can be rubbed on to the food surface, mixed into foods dry (dry curing), or dissolved in water (brine, wet, or pickle curing)

• In the latter processes, the food is submerged in the brine until completely covered . With large cuts of meat, brine may also be injected into the muscle .

Pickle

has been used to mean any brine solution or a brine cure solution that has sugar added

Plasmolysis

• Salt inhibits microbial growth by this process.

• In other words, water is drawn out of the microbial cell by osmosis due to the higher concentration of salt outside the cell

• A cell loses water until it reaches a state first where it cannot grow and cannot survive any longer

TRUE

TRUE OR FALSE: A common method of treating freshly cut meat is the addition of salt, this process of corning inhibits the growth of bacteria and other microorganisms keeping the meat odor less and reduces the water retention .

Dry curing

• works best when the meat is cut into smaller pieces with salt and placing the meat in a tightly sealed plastic storage bag.

• Remove the excess salt before cooking with a through rinse, in case there is excess salt, boil or soak the meat or reduce the curing time .

Brine Curing

• involves the creation of brine containing salt, water and other ingredients such as sugar, erythorbate, or nitrites.

• usually produces an end product that is less salty compared to dry curing

• injection of brine into the meat can also spread the curing process

Nitrate/Nitrite Curing

• Most salt cures do not contain sufficient levels of salt to preserve meats at room temperature and Clostridium botulinum spores can survive.

• In the early 1800's it was realized that saltpeter (NaNO3 or KNO3 ) present in some impure curing salt mixtures would result in pink colored meat rather than the typical gray color attained with a plain salt cure.

N-nitrosoamines

• were considered carcinogenic in animals.

• For this reason, nitrate is prohibited in bacon and the nitrite concentration is limited in other cured meats.

dietary inorganic nitrate

represent a promising complementary therapy to support hypertension treatment with benefits for cardiovascular health.

Smoke Curing

• In this method of meat curing the meat is directly exposed to smoke from burning or smouldering plants or wood

• if the smoke is persistent and hot enough to slow-cook, it keeps the meat tender

• can be combined with other methods such as salting, this creates a layer above the meat sealing any entry for bacteria.

Prague Powder #1, Insta Cure, or Modern Cure.

This cure contains sodium nitrite (6.25%) mixed with salt (93.75%). Consumers are recommended to use 1 oz. for every 25 lb. of meat or one level teaspoon of cure for 5 lb. of meat.

Prague powder #2

• This mix is used for dry cured meats that require long (weeks to months) cures. It contains 1 oz. of sodium nitrite and 0.64 oz. of sodium nitrate. It is recommended that this cure be combined with each 1 lb. of salt and for products that do not require cooking, smoking, or refrigeration.

• This cure, which contains sodium nitrate, acts like a time-release cure, slowly breaking down into sodium nitrite, then into nitric oxide. The manufacturer recommends using 1 oz. of cure for 25 lbs. of meat or one level teaspoon of cure for 5 lbs. of meat.

Saltpeter, Sodium or Potassium Nitrate

• commercially, nitrate is no longer allowed for use in curing of smoked and cooked meats, non-smoked and cooked meats, or sausages (US FDA 1999).

• However, nitrate is still allowed in small amounts in the making of dry cured uncooked products. Home food preservers should avoid the direct use of this chemical and opt for the mixtures described above.

Combination Curing

• Some current recipes for curing have vinegar, citrus juice, or alcohol as ingredients for flavor.

• Addition of these chemicals in sufficient quantities can contribute to the preservation of the food being cured.

Salt

This flavor is the most predominant

Sugar

• Serves to reduce the harshness of the salt in cured meat and enhance the sweetness of the product.

• Also serves as a nutrient source for the flavor-producing bacteria of meat during long curing processes.

Spices and flavor enahncers

• add characteristic flavors to the meats.

• recent studies have suggested that some of them can have added preservative effects

• However, the quantities needed to achieve these effects may be well beyond the reasonable quantities of use.

Nitrates/Nitrites

Provide the characteristic cured flavor and color

Fermentation

The tangy flavor observed in dry fermented sausages, such as pepperoni, is the result of bacterial fermentation or the addition of chemicals such as glucono-δ(delta)-lactone

Smoking

gives the product the characteristic smoky flavor that can be varied slightly with cure recipes and types of smoke used.

TRUE

TRUE OR FALSE: A high concentration of salt promotes the formation of an unattractive gray color within some meat.

TRUE

TRUE OR FALSE: Nitrate when used for some dry-cured, non-cooked meats is reduced to nitrite then to nitric oxide, which reacts with myoglobin (muscle pigment) to produce the red or pink cured color.

TRUE

TRUE OR FALSE: If nitrite is used as the curing agent, there is no need for the nitrate reduction step, and the development of the cure color is much more rapid.

Cure accelerators

• tend to speed up chemical conversion of nitric acid to nitric oxide.

• They also serve as oxygen scavengers, which slow the fading of the cured meat color in the presence of sunlight and oxygen.

• Some studies have indicated that THEY have antimicrobial properties, especially for the newly emerging pathogens like E. coliO157:H7 and Listeria monocytogenes (Doyle 1999)

Curing

is a broader preservation method that typically includes salt, but may also involve sugar, nitrates/nitrites, and other ingredients to enhance preservation, flavor, and color

Dry curing

rubbing the mixture directly on the meat (e.g., prosciutto).

Wet curing

soaking food in a flavored salt solution (e.g., corned beef).

Nitrates and nitrites

help prevent the growth of Clostridium botulinum and contribute to the characteristic pink color of cured meats.

Smoking meat

imparts an attractive and appealing sensory property, in addition to preserving meats.

Heat, chemical, surface dehydration

Three preservation mechanisms

Microorganisms

Heat from smoke cooking can kill ______, depending on time and temperatures used

TRUE

TRUE OR FALSE: Some chemical compounds in wood smoke have an antimicrobial effect, contributing to food preservation, but these compounds are generally insufficient by themselves

Hot Smoking

• Done in the smokehouse or more modern electric kilns, usually over a short period of time, just until the meat is cooked.

• The meat is cooked and smoked at the same time over a burning fire or electric elements of a kiln.

Cold Smoking

• is done over a much longer period of time, e.g. 12-24 hours, over a smoldering fire [(below 85°F (29.4°C)].

• the temperature does not exceed 29 °C (85 °F), and the food is not cooked during the process.

• Since foods are held in the temperature danger zone, rapid microbial growth [(40-140°F (4- 60°C)] could occur.

  • Therefore, only those meat products that have been fermented, salted, or cured, should be ____-smoked

Liquid Smoking

• Many consumers and commercial operations use liquid smoke to add smoke flavor to their foods.

• Liquid smoke has advantages over traditional smoking in that it can be more precisely controlled and the smoke flavor is instantaneous.

Lactic Acid Bacteria

• are frequent spoilage organisms on cured/smoked meats.

• They are tolerant of some of the conditions in the curing/smoking process or are contaminates after processing.

• They grow slowly but eventually spoil the food by producing organic acids

Undesirable spoilage caused by this bacteria includes:

• Greening of meat

• Gas formation in cheese

• Bloating or exploding of vacuum sealed pouches

• Off flavors – cheesy, malty, acidic, foul, sour

• Slime on meats

• Ropy beverages or dairy

Staphylococcus xylosus

Orange patches are the bacterium _______ ______ is added to salami for flavour and aesthetics (helps retain the deep red color of meat.

Penicillium nalgiovense and Debaryomyces hansenii

Mold _______ _______ and yeast __________ ________ colonize the salami and prevent contamination. Produces musty, mushroomy, and yeasty aromas.

Lactobacillus viridescens

• produce hydrogen peroxide may cause greening in meats.

Green

The H2O2 reacts with myoglobin to produce a ______ sheen pigment.

Hydrogen peroxide (H2O2)

a oxidizing agent that is commonly used in industry and in the medical field.

Slime Producers

Some Micrococcus spp. and other bacteria are capable of producing slime on the surface of hams, bacon, and sausages.

rancid flavor

Salt increases oxidation during long cures and can lead to a _________ _______. Prolonged frozen storage may also contribute to oxidation leading to _____ flavors.

Smoking

A method where food is exposed to smoke from burning wood, which imparts flavor and helps with preservation.

• Often done after curing/salting, especially in traditional methods of preserving meats or fish

Cold Smoking

Done at low temperatures (below 29°C; requires prior curing or salting since it does not cook the food.

Hot Smoking

Involves cooking the food (temperatures between 80°C and 150°C, which makes it safe to eat.

Benefits of Smoking

• Adds flavor.

• Dries the surface of food (reducing microbial activity).

• Introduces antimicrobial compounds from the smoke (phenols, formaldehyde).

Campylobacter

min pH: 4.9

max. % salt: 2

min. temp: 86F

oxygen req. microaerophilic

Clostridium

min pH: 4.7

max. % salt: 10

min. temp: 38F

oxygen req. anaerobic

E. coli

min pH: 3.6

max. % salt: 8

min. temp: 33F

oxygen req. facultative anaerobic

Listeria

min pH: 4.8

max. % salt: 12

min. temp: 32F

oxygen req. facultative anaerobic

Salmonella

min pH: 4.0

max. % salt: 8

min. temp: 41F

oxygen req. facultative anaerobic

Staphylococcus

min pH: 4.0

max. % salt: 20

min. temp: 41F

oxygen req. facultative anaerobic

Vibrio

min pH: 3.6

max. % salt: 10

min. temp: 41F

oxygen req. facultative anaerobic