Joe Sebranek. Department of Food Science and Human Nutrition 215 Meat Laboratory Iowa State University.

Transcription

1 Joe Sebranek Department of Animal Science Department of Food Science and Human Nutrition 215 Meat Laboratory Iowa State University Ames, Iowa, U.S.A.

2 Sodium reduction in processed meats is not a new issue research h in the 1960s and 1970s highlighted hli h relationships between excess dietary sodium and hypertension start of public initiatives to reduce sodium was 1969 White House Conference on Food, Nutrition and Health resulted in new dietary recommendations as well as regulatory and labeling proposals industry i d began to target sodium reduction in the 1970s and the 1980s ranging from about 15% to as high as 40% with concurrent fat reduction

3 Clearly, l this has been a continuing i issue over the past 40 years average consumption of salt in U.S. was estimated to be g/day in 1970s ( mg sodium); daily requirement is mg sodium (consumption = some fold excess) in 2010, average U.S. consumption of salt from food is 8.7 g (3407 mg sodium): estimate for Canada is also 8.7 g 1/3 of U.S. adults are hypertensive; 1/3 are pre hypertensive at age 50, lifetime probability of hypertension is 90% Appel, L.J., and C.A.M. Anderson. Compelling evidence for public health action to reduce salt intake. New Engl. J. Med. 362(7): (2010)

4 Sodium consumption appears to be closely and progressively related to hypertension High blood pressure is a major risk factor for cardiovascular diseases Cardiovascular diseases are world s greatest killers Sodium consumption also implicated in other health issues (diabetes, kidney diseases, etc.)

5 sodium from food (mg/day) 2671(66%) 2698(85%) discretionary sodium total sodium Engstrom, A., R.C. Tobelmann and A.M. Albertson. Sodium intake trends and food choices. Am. J. Clin. Nutr. 65(suppl.):704S(1997)

6 IMHO, processors may have gone a bit too far with sodium (and fat) reduction in the 1980s and created a longterm consumer perception of these products as less palatable. certainly, the market has not been well sustained Consumers may now associate reduced sodium, low sodium, reduced fat, etc. with past experiences of less palatable products and may be less receptive to new attempts to promote sodium reduction this perception p may need to be changed or avoided (silent reduction) Challenge #1

7 In the past 5 years, several new campaigns have been initiated by public health organizations in Europe, U.S. and Canada most have established consumption targets of less than 6 g of salt per day (2300 (3 mg of sodium) this is a target reduction of about 30% from current consumption levels, to be accomplished over several years (5 years is most common)

8 Dietary Guidelines for Americans (USDA) 2005 consume less than 2,3oo mg per day for individuals with hypertension, blacks, middleaged and older adults consumption should be no more than 1,500 mg/day (potassium should be consumed at 4,700 mg/day) The Guidelines are currently in review for 2010 update done every 5 years.

9 Health Canada Working Group on Dietary Sodium Reduction goal is to reduce dietary sodium to 2300 mg/day by 2016 by reducing sodium intake by 5% per year

10 Current average Proposed(max) target(%) Sausage(weiners) ( 12.4%) Deli meats ( 13.6%) Fresh sausage ( 12.5%) Uncooked bacon ( 24.6%) Cooked bacon ( 17.1%) Fermented, dried ( 13.4%) Pates and spreads ( %) 3%)

11 National Salt Reduction Initiative (2008) coalition of 45 public health departments from various cities and states, and national health organizations led by New York City goal is to work with food processors to voluntarily reduce salt by 25% in packaged and restaurant foods over 5 year period to achieve a 20% reduction in sodium intake proposed targets for various foods to be finalized this spring

12 Bibbins Domingo, K., G.M. Chertow, P.G. Coxson, A. Moran, JM J.M. Lightwood, M.J. Pletcher and L. Goldman. Projected Effect of Dietary Salt Reductions on Future Cardiovascular Disease. New England Journal of Medicine 362: (2010)

13 reducing salt intake by 3 g (1200 mg of sodium) per day would: reduce CHD by 60,000 to 120,000, strokes by 32,000 to 66,000, heart attacks by 54,000 to 99,000 and deaths by 44,000 to 92,000 save $10 $24 billion annually in health care cost The cardiovascular benefits of reduced salt intake are on par with the benefits of population wide reductions in tobacco use, obesity and cholesterol levels.

14 Henney, J.E., C.L. Taylor and C.S. Boon (eds.). Strategies to Reduce Sodium Intake in the United States. Institute of Medicine of the National Academies of Science. Released April 20, page report outlining the issues of salt in food and offering recommendations of ways to achieve reduced consumption

15 US U.S. Food and Drug Administration i ti should set mandatory dt national standards for sodium content of foods and modify GRAS status of salt and other sodium compounds Industry should voluntarily reduce sodium content in advance of the standards Revise and update sodium labeling claims and extent this to restaurants t and food service. Set a timeline for achieving the reduction goals Establish monitoring systems for sodium intake, taste preferences and sodium content t of foods

16 Recent announcements of sodium reductions in food ranging from 10% to 20% include: Campbell Soup Conagra Kraft H. J. Heinz Mars Foods SubwayS b et al.

17 Cereal products, bakery goods, breads, pastries 27% 38% Meat products 20% 21% Soups and sauces 7% 13% % Dairy foods 7% 9% Snack foods 4% 9% Desmond, E. Reducing salt: A challenge for the meat industry. Meat Sci. 74: (2006)

18 Fresh meat contains mg/100g Salt = 39% sodium Many other ingredients are sodium salts sodium tripolyphosphate = 31% sodium erythorbate/ascorbate = 12% sodium nitrite = 33% sodium nitrate = 27% monosodium glutamate = 14% The bottom line: salt contributes 75% 80% of the sodium in cured and processed meats

19 65% are concerned about sodium, 79% do not know about the recommendations of mg/day Of those concerned, control is typically done by limiting perceived high salt foods, not by monitoring daily intake of sodium Only 29% consistently look for sodium content information on food packages Challenge #2

20 For women, the perception of salt as a water weight gain factor is a greater motivator to avoid sodium than concern about high h blood pressure 78% believe that sea salt is a healthier alternative low sodium labeling may be a negative; consumers given 2 identical soup samples with one labeled 25% less sodium indicated the low sodium sample was inferior Consumers had limited interest in claims of low sodium, reduced salt and sodium free but reacted positively to reduced salt same taste Health Focus International Survey, HFI, FoodProcessing. com(2010)

21 late 1970s through 1980s brought considerable product research on sodium reduction and identified changes that facilitated less sodium in finished products

22 confirmation of the essential functional role of salt in processed meats, realization that salt is irreplaceable but reduction is possible KCl substitution (partial) compensation by phosphates preference p for salt is an acquired taste additional flavoring agents bacterial control will need to be achieved with other ingredients and processes textural compensation may be needed with other ingredients

23 Salt is an extremely fundamental, multifunctional ingredient 1. essential for expected flavor (saltiness and enhancement of other product flavors) 2. provides for protein hydration and water binding by shifting the isoelectric point of meat proteins, which results in improved juiciness, and is critical to yields of cooked products 3. solubilizes proteins necessary for fat binding and product texture, improves tenderness 4. effective bacteriostat with both pathogenic and shelf life implications 5. very economical ingredient

24 Role of sodium acquired taste preference, offers opportunity to modify taste preferences of consumers Salt also enhances other flavors in addition to contributing saltiness Research suggests that 1.7% 1.8% in processed meats becomes detectably different affected somewhat by fat content, probably due to salt/water ratio (brine strength concept) Challenge #3

25 Provides for protein hydration and water binding by shifting the isoelectric point of meat proteins to retain juiciness and provide critical control of yields of cooked products extremely important concept that is fundamental to understanding many meat processing principles

26 Bound water as % of muscle weight ph Salted Unsalted

27 NaCl dissociates in water to Na+ and Clˉ Clˉ binds more strongly to meat proteins, resulting in greater negatively charged proteins ti Protein repulsion results in swelling and uptake of water

28 Swelling Shrinking Offer, G, and J Trinick 1983 On the mechanism of water Offer, G., and J. Trinick On the mechanism of water holding in meat: the swelling and shrinking of myofibrils. Meat Sci. 8:

29 Keep in mind that the functional concentration of salt is affected by the water content of the product Brine Bi Strength th = salt / salt + water = 2.5 / = 3.45 % brine

30 In general, water binding in meat increases from 0% to N NaCl Cl(i (in water phase = 6.9%; 4.8% of meat weight ih assuming 70% water) However, in comminuted processed products, the critical reduction limit appears to be at around 1.8% 2.0% (brine) to avoid major changes in yields and texture, and is product dependent. In enhanced fresh meats, salt at less than 1.0% will improve tenderness and eating quality Challenge #4

31 Water and Fat Exudate from Meat Batters with Reduced Salt 8 6 Water Exudate Water Exudate (ml/30g) Fat Exudate (ml/30g) Fat Exudate Salt Level (%) Whiting, R.C. Stability and gel strength of frankfurter batters made with reduced NaCl. J. Food Sci. 49: , 1362(1984)

32 In cooked whole muscle products such as hams, protein swelling is restricted by the muscle structure, but 1.8% again seems to be a lower limit for salt concentration to minimize yield and textural changes Ruusunen M and E Pu0lanne Reducing sodium Ruusunen, M., and E. Pu0lanne. Reducing sodium intake from meat products. Meat Sci. 70: (2005)

33 Myofibrillar protein solubility is key to emulsion product stability, sectioned formed product binding and comminuted product texture myosin solubility requires 0.3 M or more salt (1.8% bi brine; 1.4% meat weight) iht) researchers have rep0rted a lower limit of 1.4% salt for binding of fat in emulsions and for texture in cooked sausage Challenge #5

34 Fermented sausage salt is necessary to facilitate growth of lactic acid organisms and for microbial control of the fermentation impacts production of volatiles and flavor compounds produced. Olesen et al., Generation of flavour compounds in fermented sausages influence of curing ingredients. Meat Sci. 66: (2004). Recommendations for salt use in fermented sausage is concentrations of >2.0%

35 With all else equal, salt reduction will shorten shelf life and reduce bacterial control microbial effects include reduction of Aw; 2% salt reduces Aw from 0.99 to ~0.96 to significantly suppress bacterial growth Salt reduction is likely to reduce pathogen control Interaction with other ingredients such as nitrite in cured meats is highly hl synergistic iti for impact on bacteria particularly l Clostridium sp. Challenge #6

36 Interaction of salt and nitrite on Clostridium sporogenes 1.5% 45pmm % 45pmm 1.5% 150pmm Pouches with Gas (%) % 150pmm % 45pmm Storage Time (days) Whiting R C R C Benedict C A Kunsch and D Blalcock Growth of Whiting, R.C., R.C. Benedict, C.A. Kunsch and D. Blalcock. Growth of Clostridium sporogenes and Staphylococcus aureus at different tempeatures in cooked corned beef made with reduced levels of sodium chloride. J. Food Sci. 50: (1985)

37 Substitution of KCl for NaCl practical limit is about 40% 50% due to flavor impact saltiness appears to be similar at 50% or less functionality may not be equivalent NaCl is 60% Cl; KCl is 47% Cl, so KCL delivers 22% less Cl on an equivalent weight basis

38 Solubilized protein (mg/g tissue) NaCl 123.5± KCl 118.9±1.3 Munasinghe and Sakai. Sodium chloride as a preferred extractant t tf for p0rk lean meat. Meat Sci. 67: (2004) 6

39 Emulsion stability M water loss(%) fat loss(%) gel strength(g) NaCl KCl Whiting, R.C. Influence of various salts and watersoluble compounds on the water and fat exudation dti and gel strength th of meat batters. J. Food Sci. 52(5): (1987)

40 Flavor enhancers (umami) monosodium glutamate (0.5% 2.0%) nucleotides (0.05% 05% 0.2%) hydrolyzed proteins (0.5% 1.5%) yeast extracts (0.1% 1.5%) Bitterness blockers (counter potassium taste) t several commercial versions Variety of new commercial salt substitutes with a variety of claims processors need to evaluate each product for it s own merits Probably should not hope for a complete substitute for flavor flavor changes are a unique challenge in salt reduction

41 Polyphosphates highly effective for improved water binding and protein extraction and product yields impact on meat is different from salt (ph, structural protein modifications) net effect with salt is synergistic generally allows a salt reduction of up to 0.5% but the degree of improvement lessens at low salt concentrations

42 Effect of phosphates, KCl and carrageenan on thaw drip of cooked pork sausage NaCl KCl Tha aw drip (% %) Contol 6 iota CGN kappa 8 CGN lambda 4 Cgn w/o STPP w/ STPP w/o STPP w/ STPP DeFreitas, Z., J.G. Sebranek, D.G. Olson and J. M. Carr. Freeze/thaw stability of cooked pork sausages as affected by salt, phosphate, ph and carrageenan. J. Food Sci. 62(3): (1997).

43 Carbonates raise ph in meat products similar to phosphates have been shown to significantly reduce cooking losses and improve product yields have h not been evaluated in low salt products Dolata, W., E. Piotrowska and M. Krzywdzinska. The effect of carbonate preparations p on the rheological properties of meat batter and on sausage quality. Elect. J. of Polish Univ. 2(2): #07 (1999).

44 Many water binding agents available Starches, hydrocolloids, carrageenans, Konjac flour, gums, non meat proteins (soy, milk), plant fiber products Transglutaminase crosslinkingg of lysine and glutamine on proteins resulting in binding of meat pieces and increased textural firmness of comminuted meats permits up to 75% reduction of salt for texturet and binding functions researchers c e s have aereported increased ceasedyedsat yields at low salt (1.0%) but greater cooking losses at higher salt levels

45 Antimicrobial ingredients lactate/diacetatel t t t t natural fermentation products naturally fermented vinegar, fruit powders cultured corn sugar and vinegar phage many y antimicrobial ingredients have been studied and may offer future potential

46 Processing alternatives pre rigor p g meat improved protein solubility and functionality high h pressure treatments highly effective antimicrobial treatment researchers have reported improved protein functionality but protein solubility may decrease some improvements in low salt products reported added cost of $0.20 $0.30/pound

47 Treatment Cooking loss (%) 1.5% salt/70c % salt/400 Mpa/70C % salt/0.3% TPP/70C % salt/0.3% TPP/400 Mpa/70C 0.4 d i l S l d h h Fernandez Martin et al. Salt and phosphate effects on the gelling process of pressure/heat treated pork batters. Meat Sci. 61:15 23 (2002)

48 Salt content may be reduced in cured and processed meats but there are functional limits sausage products % hams/cured meats % fermented sausage > 2.0% Limits of change will depend on current concentration in each product, and will be product specific specific, processor specific, and formulation specific Decisions should be made on a case by case assessment, and a systems approach will be necessary Changes may impact product cost

49 Challenge #1 How is reduction best communicated to consumers if at all?

50 Challenge #2 Consumer education about how to use sodium labeling is critical

51 Challenge #3 Can acceptable flavor be achieved? If so, what is the necessary transition time for consumer adjustment?

52 Challenge #4 Can moisture retention and yields be maintained?

53 Challenge #5 Can protein functionality for fat binding in emulsions and product texture remain effective?

54 Challenge #6 Can bacterial safety and shelf life be maintained?

55 Challenge #7 Will the means by which the reduction is accomplished make economic sense?

56 There is no magic bullet because multiple adjustments (systems approach) will be required to compensate for the multiple li l changes that occur in multiple product properties in processed meats when salt is reduced, consequently processors will need to do their homework very carefully for each product under consideration.