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The rationale for and challenges of reducing salt in foods
1. A justificativa e os desafios da redução
do sal nos alimentos.
Dr Ray J Winger Dr Ray J Winger
Emeritus Professor of Food Technology Managing Director
Massey University Inside Foods Limited
New Zealand United Kingdom
Board member, Institute of Food Technologists, USA.
2. Outline
Importance of salt to our health
Sources of salt
What is saltiness?
Implications for product development
Technological challenges for salt use
Challenges and acheivements of reducing salt
Pragmatic lowering of salt in food
Example
4. Humans need 10-20mmole sodium/day
230 – 460mg Na/day
1g Na = 2.5g salt
580 – 1160mg salt/day
Evolutionary ancestors ate about 250mg salt/day
Civilisation development
salt played a pivotal role
preservative – allowed communities to settle
highly prized, valued, taxed – a luxury
5. Almost all Na ingested is absorbed into blood
active sodium pump
6. Almost all Na ingested is absorbed into blood
Regulates blood pressure and blood volume
blood volume 70kg man ~15litres
blood Na content ~50g
~90% of the total body Na
7. Almost all Na ingested is absorbed into blood
Regulates blood pressure and blood volume
Responsible for osmoregulation in our bodies
sodium-potassium-ATPase pump
uses a third of our bodies energy
high-Na & low-K extracellular, low-Na & high-K
inside
Involved in contraction and relaxation of muscles
8. major studies:
INTERSALT (1985-1987)
52 populations
32 countries
INTERMAP (1996-1999)
17 populations
4 countries
Several individual countries
timeline of changes in salt consumption
9. Lowest salt intake studied
Yanomamo Indians (Brazil)
0.8mmole Na/day for men (46mg salt/day)
1.0mmole Na/day for women (58mg salt/day)
Also low (<50mmole Na/day) (2.9g salt/day)
Xingu Indians (Brazil)
Papua New Guinea Highlanders
Luo (Kenya)
INTERSALT Cooperative Group. (1988). BMJ 297:319-328
Mancilha-Carvalho & de Souza e Silva (2003). Arq. Bras. Cardiol. 80 (3):295-300
10. Highest salt consumption (INTERSALT)
Korea (385mmole Na/day) (22.3g salt/day)
Japan
Northern – 462mmole Na/day (26.8g salt/day)
Southern – 239mmole Na/day (13.9g salt/day)
People’s Republic of China - 259mmole Na/day
(15g salt/day)
INTERSALT Cooperative Group. (1988). BMJ 297:319-328
11. Overall modal value (INTERSALT)
150 – 199mmole Na/day for men (8.7-11.5g salt)
100 – 149mmole Na/day women (5.8 – 8.6g salt)
Brazil has about 11g salt/day
UK and USA about 9g salt/day
INTERSALT Cooperative Group. (1988). BMJ 297:319-328
12. Need 10 – 20mmole Na/day
= 0.6 – 1.2g salt/day
Range of consumptions
1mmole Na/day to 460mmole Na/day
= 0.06 – 26.7g salt/day
Most countries consume 100 – 199mmole Na/day
= 5.8 – 11.5g salt/day
men higher than women
13. Huge day-to-day variability for an individual
>10-fold
Best data are from 24-hour urine collections
only one sample
require >6 samples over prolonged period
Impractical
Records Na (not salt consumed)
14. Blood pressure
Yanomami Indians: 95 / 61
Xingu: 99 / 62
Effective baseline target for no salt
15.
16. Salt and blood pressure
evidence is substantial
extremely controversial
about 33% population no influence at all
definite link to increasing bp with age (>60 years)
definite link to bp and renal insufficiency
unable to adequately excrete Na
17. Salt and blood pressure
Relationship to ischemic stroke
strong epidemiological evidence from Japan
Strong relationship to cardiovascular mortality
Critical for water retention
major cause of oedema in women
heart failure
left ventricular hypertrophy
increased stiffness of blood vessels
18. Stomach cancer
possible links to Helicobacter pylori
Urinary calcium excretion
kidney stones
bone mineral density
20. USA 2010 guidelines
recommend no more than 2300mg Na/day
further reduce to 1500mg Na/day for people:
51 years and older
any age and
are Afro-American
have hypertension
have diabetes
have chronic kidney disease
21. UK guidelines
10 years and older
1600mg Na/day
Key issue for all public health professionals is:
sodium to potassium ratio
used to be about 1:7 (ancestors)
now 3:1
22. Pan American Health Organisation / WHO
policy goal
target of <5g salt/person/day by 2020
20-33% of adults in Americas are hypertensive
above 80 years old this is >90%
Want standard food labelling
educating children on health risks of excess salt
23. USA market insight
45% of consumers check Na on food labels
70% used low Na foods/beverages in 2006
78% used them in 2007
Source: NMI Health and Wellness Trends Database, 2007.
26. Cereals and cereal products
breakfast cereals
bread
pasta
pizza
27. Cereals and cereal products
Meat and meat products
bacon
ham
sausages
marinades
red meat and poultry (includes natural Na)
fish and seafood
28. Cereals and cereal products
Meat and meat products
Prepared meals
restaurants
ready made meals
takeaway foods
Chinese and Indian foods
soups
sauces
29. Cereals and cereal products
Meat and meat products
Prepared meals
Dairy products
Vegetable, tomato and fruit juices
30. UK
focuses on specific food groups high in added salt
sets targets they believe are realistic
examples:
food group current Na target Na level
level mg/100g
mg/100g
pizza 600 300
cheese 700 500
bacon and ham 1491 750
burgers 503 300
sandwiches (bought) 500 350
31. UK
focuses on specific food groups high in added salt
sets targets they believe are realistic
Issue:
where salt has a key preservative role, may:
reduce safety margins in relevant foods
create unsafe food
reduce shelf life significantly (food spoilage)
increase incidence of food poisoning
32. Kraft Foods Ltd reduced salt in 1000 products
by 10% over 2 years
saved 4500 tonnes salt / year
that’s the weight of 25 jumbo jets....
33. ConAgra Foods Ltd, Nebraska
removed 2.8 million pounds from USA diet
(1,260 tonnes)
from entrees (prepared meals)
34. Salt usage Number (%) of consumers
Never Occasionally Frequently Always
In cooking 31 36 8 25
At the table 20 43 15 21
Purdy & Armstrong (2007). In: Reducing Salt in foods. Kilcast & Angus. Woodhead Publishing Ltd, UK.
35. Generally over consume Na
Under consume potassium (K)
Under consume calcium (Ca)
37. Salty taste is a response to regulating Na levels
no body stores of Na
need to respond to sudden Na-depletion quickly
Only sodium and lithium taste salty
certain circumstances – potassium, calcium
NaCl is most salty of all Na compounds
38. Salt is perceived in taste buds on the tongue
unsure exactly how in humans
involves Na-ions through a narrow ion channel?
Nerve impulses to brain
increases blood flow in specific parts of the brain
Blood hormones influence Na
angiotensin II
aldosterone
39. Salty taste is perceived on tongue
Salt also modifies perceived flavours of food
perception is in the nose
not a direct effect of NaCl as this is not volatile
modifies volatility of aroma chemicals?
40. Na-deprived animals have a compensatory
appetite for salt
NaCl pleasantness depends on other attributes
texture of food
some liquid foods (soup) better with excess NaCl
41. Acute sodium loss (eg vomiting, diarrhoea)
show reduction in perceived intensity of salt
increase in pleasantness of salty foods
42. Reduced sodium diets
after 8-12 weeks, preferred NaCl concentration is
reduced
original higher level is unpleasant
43. Clear evidence of foetal environment and salt
preferences during later life
Mothers with regular morning sickness
acute and sustained salt deficiency during pregnancy
off-spring have higher salt preference
Higher salt consumption by mother
reflected in amniotic fluid
children consume higher salt
(close correlation to mother)
45. There are no effective sodium-free salt
substitutes that mimic salt taste
Salt is used to mask bitter tastes
are there alternative Na-free masks?
Can we enhance salty taste
results in reduction of salt for same perception
46. Gradual reduction in salt over prolonged time
salt taste can be changed
requires time
requires an industry-wide coordinated effort
Never forget:
taste and flavour is the #1 consumer driver
47. The medium the Na is presented has a profound
impact on taste perception
Up to about 30% salt reduction
single main salt carrier (eg beef in a stew)
salt perception significantly reduced
acceptability ratings not changed significantly
multiple salt carriers (eg vegetable soup)
salt perception relatively similar to original
48. Complex food dishes
create a variety of tastes and flavours
30% salt reduction without affecting acceptability
Coarse texture better for reducing salt than
smooth texture
50. Preservative (5 – 20% salt)
meat
fish
pickled vegetables
mayonnaises and sauces
As a component part of hurdle technology
3-6% salt plus other hurdles (chilling, acid, etc)
51. Salt concentration water activity
% NaCl
1.7 0.99
3.4 0.98
6.6 0.96
9.4 0.94
11.9 0.92
14.2 0.90
16.3 0.88
18.2 0.86
Most undesirable food bacteria stop growing around Aw = 0.92
Yeasts and moulds are mainly controlled below Aw = 0.85
Betts et al., 2007. In: Reducing salt in foods. Kilcast & Angus. Woodhead Publishing Ltd., UK.
56. Challenges and achievements in reducing salt
The most common procedure in UK
slow, small, stepwise reduction in salt from
product formulations over a long time
from 1998 to 2005 - 33% reduction in many foods
Heinz Foods Ltd (11-18% reduction)
Kraft reduced processed cheese salt by 33%
Significant choice of no-added-salt foods
breakfast cereals
margarines, butter
57. Challenges and achievements in reducing salt
Create more complex flavour mixtures
use of herbs and spices
increase in quantity of main components
use of specific ingredients to strengthen taste
lemon
onion, garlic
vinegar and other acids
chilli
58. Challenges and achievements in reducing salt
Distinct from salt replacers (though fuzzy)
Amino acids
glycine
L-lysine and L-arginine
hydrolysed protein savoury flavours
yeast extracts
amino acid mixtures cultured products
often bitter
glutamates (especially MSG)
L-ornithine
dipeptides, tripeptides
59. Challenges and achievements in reducing salt
Amino acids
Nucleotides
5ʹ-ribonucleotides
disodium guanylate
disodium inosinate
inosine 5ʹ-monophosphate (IMP)
5ʹ-guanidyllic acid
60. Challenges and achievements in reducing salt
Amino acids
Nucleotides
Lactates
sodium, potassium and calcium lactates
Trehalose
Cargill - ASCEND™
Alapyridaine
(N-(1-carboxyethyl)-6-hydroxymethyl-pyridinium-3-ol)
61. Challenges and achievements in reducing salt
potassium chloride
most common substitute
bitter / chemical / metallic taste and aftertaste
requires masking at high concentrations
feasible in some products to 30 – 50% substitution
enormous range of bitterness sensitivity among consumers
often combined with other salts
MSG
ammonium chloride, magnesium sulphate
amino acids
62. KClean™ salt
NaCl and KCl with a proprietary
additive to mask the bitterness
NaCl , KCl
Na-gluconate
63. Challenges and achievements in reducing salt
potassium chloride
calcium chloride
need high concentration to get salty taste
comes with bitter and sour tastes
irritation and metallic taste
works OK in conjunction with NaCl (masks bitterness)
sugar and citric acid also assist
64. Challenges and achievements in reducing salt
potassium chloride
calcium chloride
Magnesium sulphate
also bitter
salty at low concentrations
often a significant component of ‘low Na’ sea salt
65. Challenges and achievements in reducing salt
potassium chloride
calcium chloride
magnesium sulphate
metal ions and sea salt
Oshima Blue (Japan)
Icelandic US$14 / 240g
Rudolf Wild GmbH & Co. Ltd
Germany
Sea SaltTrim™: Low in sodium, great in taste
contains sea salt with natural high
40% Na content of salt concentration of non-NaCl minerals
Na content ~ 45% normal salt
66. Challenges and achievements in reducing salt
Salt crystal size important for perception of saltiness
normal table salt -- crystal size 200-500microns
microfine salt – crystal size 10-100microns
nanosalt – crystal size 0.005 – 0.01microns
Smallest crystals give strongest saltiness perception
Tate & Lyle signs exclusive worldwide
agreement with University of Nottingham
subsidiary for its novel salt reduction
technology
nanosalt
67. Challenges and achievements in reducing salt
Salt crystal size important for perception of saltiness
Emulsion technology
oil-in-water emulsion versus water-in-oil emulsion
when water is external continuous phase (oil-in-water)
much more salty than water-in-oil
Emerging emulsions:
water-in-oil-in-water
small volume of external water phase could be very salty
major internal water phase no salt
saltiness perception from external water phase only
overall salt content can be significantly reduced in the food
68. Challenges and achievements in reducing salt
Replacing sodium with potassium salts
use of potassium bicarbonate for baking
modification of polyphosphates
KUDOS™ Potassium Bicarbonate
BENEPHOSTM
Sodium potassium hexametaphosphate
to replace
sodium metaphosphates
70. Challenges and achievements in reducing salt
There are 25 G-protein coupled receptors for bitterness
also called TAS2R
shows importance of bitter taste to human survival
identifies potential toxic chemicals and poisons
Totally different perception mechanism than salt
salt and sugar decrease perception of bitter
IMP and GMP increase impact of MSG on umami taste
71. Challenges and achievements in reducing salt
Adenosine monophosphate (AMP) reduces KCl bitterness
Givauden Flavors
GIV3616 – a new chemical blocker of bitterness
Yeast hydrolysates
Prime Favorites
NeutralFres®
blocks KCl bitterness
73. Identify goals
who is your consumer?
why are you doing this?
introducing a new variant (no, or low salt)?
changing your existing products?
What are your competitors doing?
are there products already there?
are they selling well?
what level of change are you envisaging?
can you differentiate from competitors (price, etc)?
74. What are the sources of sodium in your product?
not all sodium is NaCl
animal foods all have high natural Na
some plants have higher levels than others
many food additives have sodium
The only reliable ‘salt’ measurement in foods is
Na
What is your target Na reduction?
75. Are you wishing to reduce Na in existing
products?
or are you creating a new version?
Consumer test your products
understand what happens as you change Na
levels
what can be perceived
what affects acceptability (may not be salt!)
76. Can you make a health claim?
low sodium
reduced sodium
very low sodium?
What’s your marketing message?
clarity?
stealth?
78. Products designed for people with renal disease
require no added salt
for reducing hypertension
reducing fluid accumulation
reducing cardiovascular damage
cannot use salt replacers (K is deadly to these people)
Complete meal to compensate for lethargy
lack of adequate kidney functionality
accumulate toxins in blood
tiredness associated with toxin accumulation
79. Formulations:
no added salt
careful selection of ingredients
increased protein component
added herbs and spices
Create multicomponent formulations
Spice levels a bit higher than normal
80. Beef casserole
30
Frequency of responses
25
20
15 Appearance
10 Aroma
Flavour
5
0
1 2 3 4 5 6 7
Degree of liking 1= dislike extremely; 7 = like extremely
30
Thai chicken curry
25
Frequency of responses
20
15
Appearance
10 Aroma
Flavour
5
0
1 2 3 4 5 6 7
Degree of liking
