Rational Dictionary of Food Science

By giosue della porta

A dictionary of easy consultation on topics and issues of food science. The characteristic feature of this dictionary are the constant references between the entries that transform it into a short but complete manual of food science.

The definitions adopted in this dictionary are in accordance with the current knowledge on the topic of nutrition, but the Author strongly believes that these definitions should not be definite or immutable as if they were dogmas of faith. The proper way to interpret them is the way of hypothesis work; to subject them to verification by the scientific community and to wait until their confirmation or contradiction. This is the mandatory itinerary of the scientific progress. The proclamations that are not based on facts they do not belong to science.

• Language: English
• Publisher: BadPress
• Release date: Jan 16, 2017
• ISBN: 9781507169094

Book preview

CONTENTS

Nutrition from A to Z

A

Adapted milk 11

Additives 12

Amino acids (see Proteins)12

Anorexia (see Eating Disorders) 12

Antioxidants 12

Aromatic Herbs (see Vegetables) 13

Atherosclerosis 13

B

Barley 15

Beer 15

Bioavailability 15

Biotechnology 15

Body mass index (BMI) 16

Bread 17

Breast Milk 18

Breastfeeding diet 19

Bulimia (see Eating Disorders) 19

Butter 19

C

Caffeine 20

Calcium (see Minerals) 20

Calories 20

Carbohydrates (see Glucides) 21

Cellulose and hemicellulose (see Glucides) 21

Cereals 21

Cheese21

Cholesterol 22

Chromium (see Minerals) 24

Cocoa 24

Coffee 25

Cold cuts 25

Corn 26

Cream 27

D

Dextrin (see Glucides) 28

Diabetes 28

Diet 28

Diet and cancer 29

Diet and obesity 30

Diet for elderly people 32

Diet in the first year of life 32

Diet from the second year of life onwards 33

Diet in adolescence 34

Diet in pregnancy 35

Dietary fiber 37

Dietetics 40

Digestion, absorption and assimilation of nutrients 40

DOC, DOP, IGP 42

Drupe 43

E

Eastern diets 44

Eating disorders 44

Egg  45

Energy (or Calorie) needs  46

Enzyme 46

Epidemiology 46

F

Farro 48

Fat (see Lipids) 48

Fat substitutes 48

Fat-soluble vitamins 48

Fish 49

Fluoride (see Minerals) 49

Food 49

Food groups 50

Free radicals 51

Freezing 52

Fructose (see Glucides)52

Fruit 52

G

Galactose (see Glucides) 54

Glucides54

Glucose (see Glucides)56

Glutamate56

Glycemic index56

Glycogen (see Glucides)57

GMOs (see Biotechnology)57

H

Honey58

Hulled wheat58

Hunger58

I

Insulin59

Insulin Resistance59

Iodine (see Minerals)59

Iron (see Minerals)60

L

Label61

Lactose (see Glucides)61

Legumes62

Lipids62

M

Macrobiotics65

Mad cow disease (BSE)65

Magnesium (see Minerals)65

Malnutrition66

Malt66

Maltose (see Glucides)66

Manganese (see Minerals)66

Mannose (see Glucides)66

Margarine67

Meat67

Mediterranean diet68

Metabolic syndrome70

Metabolism71

Milk71

Millet73

Mineral waters73

Minerals74

Molybdenum (see Minerals)75

N

Needs76

Net Protein Utilization (NPU)76

Nutrients76

Nutrition77

O

Oat79

Oil79

Olestra (see Fat Substitutes)79

Olive oil79

Olive oil (nutritional value)81

Organic farming82

Organic products (see organic farming)82

Orlistat83

Orthorexia83

P

Pasta Foods84

Pectin (see Glucides)84

Phosphorus (see Minerals)85

Phytosterols85

Polysaccharides of algae (see Glucides)85

Prion85

Probiotics (Probiotic Foods)85

Proteins86

R

Rice88

Ricotta (soft Italian white cheese)88

Rye89

S

Salt consumption and hypertension 90

Scurvy90

Seed oil91

Selenium (see Minerals)91

Sibutramine91

Sodium nitrite92

Sodium, potassium and chlorine (see Minerals)92

Sorghum92

Starch93

Starch (see Glucides and Cereals)93

Sucrose (see Glucides)93

Sugars (see Glucides)93

Sulfur (see Minerals) 93

Sweeteners93

T

Tea95

Triglycerides95

Triticale96

V

Vegetables97

Vegetables98

Vegetarian diet98

Vinegar98

Vitamins99

W

Water 100

Water-soluble vitamins 101

Wheat (see Cereals) 102

Wine102

Y

Yogurt104

Z

Zinc (see Minerals)105

Essential bibliography106

Introduction

The definitions used in this dictionary are in accordance with the current knowledge on nutrition.  They are not definitive.  Unchanging and unchallengeable are only the dogmas of faith.  On the contrary in science the ideas change with the progress of knowledge.  For example, the Euclidean geometry which was thought eternal was replaced by the Riemann geometry when the theory of relativity introduced the concept of curved space-time (it is known that the Euclidean geometry was suitable to describe mathematically only flat surfaces). Among other major examples we can include the overcoming of Newtonian mechanics by quantum mechanics and the Copernican revolution which put aside the Ptolemaic system and so on.

What can be learned by the history of scientific ideas is that we must be very careful to consider as truth to follow every single announcement of new discoveries, especially in the food sector where the afterthoughts are daily as a result of new studies and researches. Doing so will avoid the adaptation of rigid eating behaviors that are stubbornly defended even when the knowledge that inspired them has been abandoned long ago.

Scientific knowledge and press responsibility.

Naturally, the discoveries in the field of nutrition attract great interest which is overly fueled by the press that is always seeking for sensational news. One example is the campaign sponsored by the media about the dietary supplementation with a mixture of antioxidants; all united in one product without knowing exactly under which criteria. Since the first printed edition of this dictionary I always considered hasty placing on the market supplements against free radicals.  And this because we still know little about antioxidants: not all those present in nature are known and those that are known are still being studied. The composition of the antioxidants in many plants used as foods is known, but little is known about how they act, whether they act alone or in combination with all the other contents of the plant. It is therefore obvious that the choice of associating antioxidants in a food supplement is at the moment arbitrary.  It should also be kept in mind that the dietary integration with prepared antioxidants can either inhibit oxidations or, paradoxically, favor them in relation to the concentration of certain metal ions contained in the diet.

A final consideration: the free radicals perform useful actions to the body and can be harmful only if they are produced in excess. And this explains the reason for which the antioxidants, that are their antidotes, are not always beneficial but they can actually be harmful. An extended metanalysis published in the JAMA indicates that some antioxidants taken through diet can paradoxically increase the risk of death. According to Bjelakovic (doctor at the Copenhagen University Hospital) even though the oxidative stress has a role in the pathogenesis of many chronical diseases, it could also be a consequence. Eliminating free radicals probably interferes with some essential to the body defensive mechanisms (reported by The sciences, February 28, 2007). Recent news on the possible harmfulness of the antioxidants was reported by the press with a shocking title:  Counter order, the antioxidants can kill.   And this is exactly the point: if orders are given upon researches that are still in progress, it should not be a surprise if afterwards there could be a need of issuing counter orders.

So should we stay away from antioxidants?  Of course we should not.  But we should simply not consume them in the form of food supplements, at least for now, and preferably consume them in the broadest mix possible as they are in nature in vegetables and fruit.

Another mistake of the scientific information press is that of advising everyone the same dietary rules, when they should be limited to smaller groups of the population.

The demonization of cholesterol is a classic example.  A yogurt producer is fighting, in these days, his own battle, a ruthless battle, against cholesterol, considering it a perennially in ambush enemy. To make things clearer, he is broadcasting a video in which a poor man is seen followed by a brigade of silent killers wearing a yellow uniform (color symbolizing the cholesterol) from which two left eyes appear. The advertisement of his yogurt follows which has the capability of destroying the enemy. It is beautiful and good terrorism. The cholesterol problem is in the following terms. Its concentration in the blood is regulated mainly by the internal balances between production and elimination and only in part from dietary sources, (the amount produced by the body is four times greater than the one introduced by foods). This has a precise explanation: the cholesterol is an essential substance for the body, and is also the precursor to vital hormones and for this the body produces it so as not to run the risk of being without it. When the cholesterol requirement is satisfied, a receptor system blocks its production, while keeping constant the cholesterol. This receptor system is congenitally defective in the familial hypercholesterolemia and is characterized by high levels of blood cholesterol, slightly sensitive to the reduction of food intake. In the less severe form of the disease only half of the receptors work and it affects one out of 500 individuals.  The recommendation of not taking more than 300 mg per day of cholesterol is still valid if risk factors for heart attack coexist, but there is no reason to extend it for people in good health and without defects to their receptor system (see the entry cholesterol).

The paleolithic diet: a blatant reverse for weight loss.

Sustained by Boyd Eaton, an American anthropologist and nutritionist, the paleolithic diet as the name implies is the food regime of the paleolithic human who was defined as a hunter-gatherer until 10.000 years ago, the period in which is believed that the cultivation of cereals begun. That diet consisted vegetables (about the 60% of the calories), wildlife meat, fats, fibers (at least four times the recommended amount today), walnuts, almonds, nuts and legumes. In the Stone Age milk, dairy products and also cereals were not part of the diet because the pastoralism was not yet practiced.

The reason for which the people of today should return to feed like the cave man would lay to their inability to use the new foods because only a few years have passed to determine in their DNA the appearance of genes that favor their use. In other words, no genetic mutation has occurred. Therefore, the only allowable foods include meat, fish and seafood without limitation, fresh and dried fruit and vegetables in abundance. With minor variations the list of allowable foods is the same for other diets that are inspired by the Paleolithic diet (Dukan diet, Briffa and other diets).

Meanwhile, it should be specified that the Paleolithic man already ate wild cereals more than 100,000 years ago. The team of Julio Mercader, a researcher of the Department of Archaeology, University of Calgary, Canada, has recently discovered in a cave in the region of Lake Niassa, Mozambique, unequivocal evidence of the diet of the Homo sapiens in the area dating to about 100,000 years ago. Surely these ancient ancestors ate meat (as evidenced by animal bones) but ate mostly vegetables and it was also discovered unexpectedly that they ate wild sorghum, an ancestor of the cereal that is still consumed today in Sub-Saharan Africa. Certainly, the use of the starch has been an important step in human evolution because it improved the quality of the diet.

Another key point: it is not true that in 10,000 years genetic mutations favoring adaptation to changes in dietary habits cannot occur. We have proof that this is possible, as proven by the case of the persistence of lactase (the enzyme that enables the hydrolysis of lactose, the milk sugar) in certain populations involved in pastoralism, where the appearance of a genetic mutation occurred (see the entry Lactase).

As for the excessive consumption of meat we can agree on one thing: without meat the human brain would not have reached its current size. This, however, does not mean that man should eat it with no measure. Studies show that the proteins should not exceed the 2% of the daily calories, while in these diets they exceed an average of 35% (even 55% in certain diets).  And then, are we sure that this high consumption of protein has no risks?

The traditional Italian diet and the vegetarian diet do not make you fat if you keep an eye on the scale. The multiplication of needless weight loss diets is due to, according to doctors and researchers paid by the weight loss industry (a successful expression by Eric Oliver, author of many publications on the epidemiology of obesity in the United States), the growing prevalence of obesity and the consequent reduction in life expectancy. While recognizing that severe obesity is a risk factor for cardiovascular diseases, these doctors and researchers have overestimated the problem and mistakenly judged overweight more than sixty million Americans for the sole purpose of supporting the prevalence of the disease.

To avoid these overestimations, we must specify that people are overweight with a body mass index between 25 and 30, while they are obese those with an index above 30.  The increased risk of cardiovascular diseases concerns people with severe obesity, with an index of more than 35.  Overweight people are not at risk and are also not at risk obese people with an index between 30 and 35.

A

Adapted milk

By saying adapted milk we mean the cow's modified milk in its chemical composition so as to resemble the human milk which becomes therefore suitable for feeding newborn babies. The characteristics of the adapted milks have been specified by a committee of European experts in 1977 and have been updated multiple times since then.

The adaptation of the cow's milk requires complex procedures; very different from the simple dilution performed at home which was used in the past because its components are significantly different from those of the human milk in both quantity and quality. In fact, the cow's milk has a lot of casein and little serum protein, it has different fats that are little absorbable, too much phosphorous and little calcium. The iron present is in a little usable form and the vitamins are a few as well. The low amount of vitamins also depends on their destruction after the boiling or sterilization processes. The amount of linoleic acid present in the cow's milk is sufficient for the maturation of the calf’s brain, but it is completely inadequate to mature a baby's brain which is certainly more complex than the one of a calf’s.

Additives 

They are natural or artificial substances added to food to enhance its appearance, aroma, flavor and preservability. Especially under this aspect the additives have an important role because the foods are subject to environmental factors (temperature changes, oxidation and exposure to microbes) that can change their original composition.

The additives are distinguished according to their function in:

preservatives (they increase the lifetime of the product by preventing the development of microorganisms or alterations caused by oxidation),

thickeners (they increase the thickness of the food),

emulsifiers (they permit the stable dispersion of one substance into another in the case in which the two substances are not miscible with each other, such as water and fats),

flavorings (they give the food a distinctive flavor or enhance the natural flavor),

colorants (they give the product a color deliberately chosen or enhance the natural color).

The use of additives in the food industry is regulated by law. In Italy about twenty colorants and about a hundred of additives belonging to the classes listed above are allowed. According to international agreements the label must include the name of the additive, the class and a code (a three-digit number preceded by the letter E). For example, the E200 code is to indicate the sorbic acid. The number following the letter E responds to classification criteria. The colorants for example are included between E100 and E199. Today we tend increasingly to indicate on the label the name of the additive rather than a code which is incomprehensible to the consumer.

The ideal additive must be free of toxic effects and must have a valid technical justification. Unfortunately, many of the widely used additives, even if devoid of toxicity, can produce unpleasant effects such as allergies, asthma, gastric and intestinal disorders and so on, while others, considered to be harmless, can become toxic if used in excessive doses. For this reason, the laws also specify the amount of additive permitted for a particular food (the maximum daily dose should be the hundredth part of what proved harmless to guinea pigs). Also the safety of additives is subject to continuous revision in parallel with the increasing knowledge of their effects on health.

The use of additives is not something new. In fact, even the ancient Egyptians used saffron to color foods. The first additives, still used in food preservation today, both domestic and industrial, were some substances used for other purposes, such as salt, vinegar, alcohol, oil, etc. The Romans used saltpeter (potassium nitrate) in the preparation of cold cuts to avoid the browning of the meat, and also to avoid possible poisoning. Nitrites and nitrates are still the additives commonly used in industrial meat processing. The addition of nitrite or nitrate is required to prevent the growth of C. botulinum and the discharge of its dangerous toxin.

Nitrates and nitrites are already widely present in nature in the waters and plants so their addition to foods must be contained within the limits allowed by law because they may give rise to the formation of nitrosamines in the body which can be potentially carcinogenic. The maximum amount allowed by law is equal to 250 mg/kg for sodium nitrate and 100 mg/kg for nitrite. The Italian salami contains much less