Laurence Eyres FNZIFST

ECG Ltd December 2013

Depending on what kind…. ◦ Omega 3 fatty acids (fish oils-EPA, DHA;

plant sources -ALA) ◦ Mono-unsaturated fats (canola and olive oils)

Decreased fat consumption since the 1960’s associated with obesity epidemic—CHO intake has increased dramatically

Glycemic index/glycemic load Consumption via Retail oils-bottles or solid fat in tubs Retail spreads Take away foods/restaurant food Baked goods

Cost and quality

Stability

Crystal structure

Nutrition-saturated fat and cholesterol

Environmental issues

GM

Trans fats

Culinary oils Saturated fat Monounsaturated fat Polyunsaturated fat

(cold pressed)

Olive oil 15 80 5

Avocado oil 12 80 8

Flaxseed oil 8 18 74

Walnut oil 10 21 67

Macadamia nut oil 13 83 4

Hazelnut oil 9 80 11

Hempseed oil 9 12 78

canola oil 8 60 32

pumpkinseed oil 20 30 50

RBD rice bran oil 25 37 38

Hazelnut oil

Walnut oil

Extra virgin Olive Oil

Avocado

Flaxseed

Hempseed

Cold pressed NZ canola-high quality

Low in saturated fats <20%

Adequate essential fatty acids

Low in oxidation products (no rancidity)

Contains other functional ingredients such as antioxidants

Been subject of clinical trials or epidemiological studies

Tastes great so you consume it regularly

In a new study, researchers from the University of Otago, Wellington analysed the data from several international studies examining the links between saturated and polyunsaturated fat and cardiovascular disease. They then applied their findings to the average New Zealand diet, and determined that switching just 5% the daily energy intake from saturated fats to polyunsaturated fats could lead to a 10% decrease in heart disease.

Australian and New Zealand Journal of Public

Health

Volume 37, Issue 4, pages 329–336, August 2013

Fatty acids Coconut Medium chain triglycerides

Butyric 4:00 0 0

Caproic 6:0 1 <2

Caprylic 8:00 9 50-80

Capric 10:00 7 20-50

Lauric 12:00 47 <3

Myristic14:00 16.5 <1

Palmitic16:00 7.5 0

Stearic18:00 3 0

Oleic18:1 cis 6.4 0

Moisture

FFA as oleic acid

PV –initial stages of oxidation

Melting Point

SFC done by NMR

Frying is a demanding process

180 degrees Celsius

Polyunsaturated fatty acids deteriorate rapidly

Linolenic (18:3) should be less than 3 %

Natural antioxidants play a part in stability

oxygen, heat, water

VOLATILE

PRODUCTS

Aldehydes

Hydrocarbons

Alcohols

Ketones

Methyl Ketones

Pentyl Furans

Carboxylic acids

Lactones

* potato chips fried

pyrazines

NON-VOLATILE

PRODUCTS

Polar & Nonpolar

Free Fatty Acids

Cyclic Fatty Acids

Dimers

Hydroperoxides

Oxysterols

FATS DECOMPOSITION

PRODUCTS

Parameter Specification How the processor

delivers

Phosphorus < 1 mg/kg or

better still ND

Efficient degumming +

bleaching

Free Fatty

Acids

< 0.05 % oleic

acid

Alkali or physical

refining

Peroxide Value < 1 meq O2/kg good bleaching +

nitrogen sparging

antioxidants

Soaps Traces Citric acid and bleaching

Metals Fe < 0.1 mg/kg

Cu < 0.02 mg/kg

Efficient chelation and

bleaching

Virtually all available frying oils were used ◦ Edible Beef Tallow, Palm, Soy, Cottonseed, then

Canola. Market leader was Chefade (refined tallow)

Cholesterol fears saw the gradual decrease in the use of animal fats-but Chefade was economical and long lasting

Growth in the QSR-McDonalds used Deodorised beef /cottonseed

Tallow replaced by palm

Now palm being replaced by liquid oils

Edible tallow

Refined Tallow

Palm oil or palm olein/HPOl

Cheap imported liquid oils (SBO,canola)

Blends of physically refined oils-high oleic

Rice bran Oil

Retail oils-SBO,SFSO, Rice Bran Oil, Canola, Olive, Avocado, Flaxseed

QSR High oleic acid oils-Frying Oils

Industrial Food Oils-Palm, Coconut, sunflower,canola,cottonseed

Margarines and shortenings (Palm a major constituent)

Brass fittings

Wrongly calibrated thermostats

Long periods of non-use heat left on

Sulphur dioxide in the potatoes

No filtering

Lots of fatty chicken being fried

Fractionate crude tallow at 39 degrees

Alkaline refine and bleach

Hydrogenate 2-3 IV units

Post filter and post bleach with citric acid

Deodorize at 180 degrees

Final colour 5.0 Y0.5R

FFA <0.07%

Add TBHQ,1 ppm silicone, citric AOM 100 hours

Eyres, Food Industry Magazine (1986)

Intake of 1-hour oxidised PUFA appears to activate the endothelium in CAD patients (increase in plasma VCAM-1 levels).

This may be due to increased oxidative stress as indicated by increased plasma peroxides and decreased resistance of serum to oxidation

©University of Otago 2003

Oil type DO temp.

(°C)

DO time

(hours)

C18:2

Degree Isom.

C18:3

Degree Isom.

Soyabean 226 2 0.37% 5.7%

Sunflower 223 2 0.24% ND

Canola 226 2 0.21% 5.1%

Canola 246 2 1.7% 20.8%

Isomerisation level – Industrially Deodorised, Refined, oil samples

Source: Kemeny et.al., JAOCS, 78(9), 973-979 (2001)

Total deodoriser induced trans fats typically 1% or less

Margarines (80% fat) are not made any more –all spreads-fat contents 45-70%

Used to contain 11-15% trans monoenes. Not now

Now contain 20% interesterified saturated fats

Use olive oil, sunflower, soybean ,canola, rice bran oil

Plant sterol spreads a profitable niche

Margarines contain 16% water

Shortenings are dry fats

Most commercial biscuit fats are now anhydrous palm based fats

Commercial pastry fats are predominantly tallow based for performance

Cocoa butter substitutes-palm fractions and shea butter stearine

Compound fats based on hydrogenated palm kernel stearine (high in lauric acid)

Hard fats but melt in the mouth

Nutritional issue is with partially hydrogenated vegetable oils

In USA foods contained fats that had 40% trans

This issue never arose in NZ

Average intake of trans in NZ is 1-2 g per day

Butter and animal fats are sources of natural trans due to ruminant metabolism

Have to be plasticized in special plants for texture

Cake ,biscuits and pastry all require different melting points, solid fat contents and crystallisation properties

Texture deterioration-bloom in chocolate or shortbread

Oxidative rancidity which analyses ?

Hydrolytic rancidity-due to lipase

Analysis

Extraction-free fat or total lipids?

Biggest source of dietary fat in the Western world (45% saturated FA)

No trans fats and adequate EFA

Red palm oil has high levels of Vitamin E and tocotrienols plus carotenoids

Mostly consume RBD palm products with little carotenoids and reduced Vitamin E although contains tocotrienols

A growing nutritional area of study

Polyunsaturated fats are unsuitable for high temperature frying

Polar oxidised material and oxidised tallow atherogenic

The Med diet relies on EV olive oil with high levels of polyphenols

NZ consumes imported oxidised olive oils with depleted polyphenol levels (if any at all)

More than 19,000 scientific papers have been published on omega-3s, including 2,000 randomized, controlled trials in humans. The ability of EPA omega-3s to reduce triglycerides( now on drug register) is well-documented, but because EPA and DHA are an integral and structural component of cells, we are still learning about the full extent of the beneficial health effects they exert.

Two imbalances in food choice

cause damage & disease & death

Prevent the two food imbalances

and prevent the damage & distress

Here’s a simple idea

NZIC oils and fats website www.oilsfats.org.nz

AOCS website

Food NZ