6-The taste of fresh food

The majority of consumers agree that the taste of food has decreased a lot in recent years. This is probably true, but we have to consider that there is a great subjectivity in there, and the memory can be very misleading. It should be added that the remembrances of childhood taste are often associated with pleasant or unpleasant sensations that affect the memory of the reality. I am not looking for excuses, but it is a reality that increases the impression of quality loss.

I will focus on the elements that influence the taste. I'll mostly talk about fruits and vegetables, which I know better quality factors, and in the end, I add some details concerning animals.

The classification of factors is not randomly chosen, they are put in order of influence on taste.

First factor : the variety

It is called also "vegetal material". This is what will determine the taste potential of food. The taste of food is part of its genetic potential, as well as the majority of its characteristics (size, firmness, color, texture, juiciness, flavor, sugar/acidity balance, skin, etc.). Whatever the culture conditions, a variety only can express what is in its genes, even about taste.

Poor variety will always be poor; put in optimal conditions, it is only less bad. By cons, poorly managed, it can become unpalatable.

A very good variety can only be good, or become great. It is at this difference that other criteria may meddle.

Second factor : the maturity

The state of maturity will enable the variety to express its full taste potential, or not. Each type of fruit or vegetable and each variety have its ideal harvest time, which is when it gets to the point of balance between all the elements that constitute the taste.

One of the most typical cases is the pear. For most varieties of pear, the ideal point of maturity is several days before physiological maturity. Why? Because this is the time when the balance between the texture of the flesh, the development of flavors and sugars is the best. We must therefore pick the fruit at this time and mature it before consumption.

What would happen if the fruit is let more time on the tree? The approach of physiological maturity causes a natural ethylene production by pips, which will disrupt the aromas and reduce its eating quality.

What would happen if we eat the ripe picked fruit, but not matured? The texture of the flesh is too hard, sometimes grainy, with too high acidity, aromas still partially hidden. It will be a tasteless fruit, without interest.

Pick a ripe fruit does not always mean pick it mature, but at the best moment to take advantage of all its qualities.

Third factor: the climate of the year

Operates a plant through photosynthesis, so thanks to the sunlight. A very covered weather during the last phases of the cycle will reduce the taste of the variety.

Similarly, excessive rains will not allow the plant to absorb the nutrients it needs, causing some "dilution" of the organoleptic quality.

A too cold weather, or too hot, strong alternations of heat and cold, hail, is all meteorological phenomenon that disrupt the plant life and do not allow it to feed its fruits properly.

It is obvious that the farmer has little power over these factors, except in some cases. He can install anti-hail nets, or grow under greenhouses, so as to artificially create a climate that suits the culture.

Fourth factor: the soil

The term terroir is a French word used to describe an agricultural production area that is particularly characterized by the criteria of geographical area, terrain, soil, subsoil, microclimate and exposure. With vines, the soil is essential. Why? Because it is a generally non-irrigated or little-irrigated crop, so almost entirely subject to the agricultural and natural climatic conditions of the place where it grows. This is also true for all crops grown under similar conditions (olives, apricots, almonds for example, if they are grown in traditional conditions).

For cons, the importance of terroir greatly reduces with fertilized and/or irrigated crops, since the farmer brings to the plant, "comfort" it does not always naturally find.

There is however some special cases, as is the case of the Golden apple. Deemed tasteless into the 80s, it became good to very good, depending on the production area. This variety is very sensitive to the terroir, and mountain areas can produce a very high quality. Thus, in Europe, the most suitable areas are the Limousin and Savoy in France, and the Aosta Valley and South Tyrol in Italy. Other countries develop their own suitable areas for a high quality level (Somontano area in Spain, Lake of Constance in Germany, some areas of Oregon and Washington states in the United States, etc.).

Fifth factor: the culture conditions

For optimum quality, the farmer must try to equilibrate the culture. That is to say that the relationship between vigor and production must be optimal, the number of leaves per fruit has to be sufficient (the leaf is the supplier of almost all elements whose fruit needs). Excessive vigor weakens the fruit and reduces its quality. Lack of vigor will generally increases the quality of fruit, but also reduces its size, reduces productivity, and reduces the ability of the plant to renew its productive organs. But it also depends on the causes of the lack of vigor. If there is a problem of drought, root asphyxia by water excess or a health problem, the quality may decrease.

The photoperiod also acts on the plant. This is the day length evolution (shortening or lengthening, depending on the season). This is the main landmark of the plant on the season in progress. It is especially observable to annual crops, because perennial crops are naturally following its biological cycle. We must plant the annual crop at the right time so that the plant is in suitable conditions. If not, the crop is generally able to grow, sometimes with problems, but the crop will not have the required quality characteristics.

The most critical point, among cultural techniques, acting on quality, is the nutritional management. The plant needs definite elements at specific times in order to optimize its physiological functioning. All nutritional art of the farmer is to know (and be able) to provide the plant with nutrients it needs, exactly when it needs it, and in a necessary and sufficient quantity, without excess. And that's really hard because there are still many unknowns in plant nutrition, and climatic and agronomic conditions have a major influence on the ability of the plant to feed.

Let’s note that when we talk about plant nutrition, fertilization is included, of course, but also irrigation, that is the water supply of the plant, because water is the main way the plant has to absorb nutrients.

Sixth factor: the method of cultivation

Is there an improvement of taste with organic production? The answer is very clear, and many studies underway or completed show this: no. However, it has the very well established reputation for that. This is true, but the reasons are very different from the method of cultivation. The bottom of the problem is that markets accept a level of aesthetic presentation significantly lower for organic products than for conventional products. This fact allows growing varieties that markets usually refuse. So we go back to the first factor: the genetic basis is the basis of taste.

We can even push the argument further: take the same variety, of any crop, and optimize it in several farming systems. We can compare, for example hydroponic greenhouse (the plant is grown without soil in an inert substrate and receives all of its nutritional requirements through the irrigation system, with very specific assays using an advanced automatism), cultivation in soil in greenhouses, outdoor cultivation in soil in conventional agriculture and outdoor cultivation in soil in organic farming. This is the only objective way to measure the differences, and it is usually this kind of scheme that is used to realize scientific tests. It is obvious that the criteria for comparing the quality will be the same for each system. We will only vary the specific criteria of each production technique.

We will probably get the following results:

1 place: hydroponics

2 place: greenhouse, soil cultivation

3 place: conventional outdoor cultivation

4 place: organic outdoor cultivation

Why?

Only for the quality of nutrition. Each system has its strengths and weaknesses. But with regard to nutrition, classification is final.

But beware, these differences will always be weak.

And the idea that the result will be better because the plant is fertilized with manure is totally false. I will explain it with more detail in a future post about plant nutrition.

About animals

The factors are very similar. However, it should be added a clear and fundamental difference that distinguishes animals from plants: they move. Most of what we eat in an animal (including fish) is the meat, which is muscle. And an animal needs to move to help the muscle to properly develop and to gaining the consistency that will make it a good meat (I remind you that I am not talking about ethics or animal welfare but fresh food quality). Whatever the rearing way or technique and the care put in the farm management, the meat can achieve optimal quality only if the animal has the possibility of moving itself. And in this context, traditional farming (organic or not), in which animals have a (relative) freedom of movement, always get a significant improvement of quality. One of the best examples is the breeding of the Iberian pig, when it is made in the good way. Animals are kept in huge enclosures (several hectares, sometimes several dozen hectares), located in woods of holm oak and cork oak (called “dehesas”), and most of their food comes from the grass, and especially acorns they must seek themselves. It is only in years of severe drought, when the oaks do not produce acorns in sufficient quantity that the farmer may have to provide them with food supplements.

To eat good products, do we have to buy organic produce or go to the local retailer? People who shop in supermarkets, are they doomed to eat poorly? The change is in progress. For several years, breeders of all kinds and all countries have reinstated parents selected for their taste, in their breeding programs, trying to combine commercial quality (appearance and conservation in particular) with taste. It is a long job, but starting to show results. In the coming years, the change should be tangible. For example, the strawberry from Huelva, so criticized, rightly, for its lack of taste, should change with the arrival of new varieties, still under experimentation, which are crossing of large strawberries with wild strawberries. Similarly tasteless tomatoes in years 1980-2000 are changing with the arrival of RAF types or beef heart type varieties. These new varieties gather many qualities that make them popular products as much by the industry and by consumers. They show the ongoing changes.

Where do we find fresh quality products? To this question, I must answer in a different way than in my publication about food security. I must say that today it is difficult to ensure both food security and a high level of quality. To find fresh quality products, we have to go to the farm, to a neighborhood shop, or to the market. Why? Simply because they live of the customer. If one day you are poorly served, you will protest next time. But if it is repeated, you go from there. These are places that only live from customer satisfaction, forcing them to treat the quality they offer. In contrast supermarkets will offer a different product with a higher guarantee, but it is almost impossible to guess the quality. But the customer goes to the supermarket for other reasons, because the finds almost everything the same place, for convenience and price (in principle). It depends on the priorities of each one.

In a future post, I explain you different meanings of the concept of quality, by the actors of the sector, which will help you to understand that everyone makes quality, but not necessarily with the same idea of the final result.

5- Grafting

At last a truly lighter subject. A kind of playtime before talking about other difficult or unpleasant subjects, I still have a lot in stock...

Let's talk about ancestral techniques, more than ever actual.

What's this?

It is a technique invented by the Chinese civilizations, 3000 years ago and introduced to occident  by the Greek civilization. Aristotle speaks about it with many details in the 4th century BC.

This consists of forcing the sealing of a bud or shoot of one plant to another plant. We name bud o bud wood the aerial part and rootstock the underground part or root system.

Once the graft sealed, we let it grow, removing shoots that the rootstock naturally produces, to  force the bud wood dominance in order to allow each the role it was given. Thus, the plant develops from the bud wood, with a root system from the rootstock.

 

On the left, the plant has been grafted in a nursery in September, and planted in the plot in December. It will grow from now. We call this type of plant a "dormant budded trees".

On the right, a bud grafted in June, grown in the nursery and planted in the plot in December. We call this type of plant « a young shoot tree ». It is starting its growth.

In some cases, the rootstock rebels and produces "suckers" aerial shoots from rootstock roots or collar, which have to be removed because they tend to form another plant beside, which will create a very direct competition with the crop. The collar is the point of separation where the underground wood changes its root structure to become aerial wood.

 

Here a peach tree whose rootstock, plum type, produces many suckers. We have to remove them because they could weaken the tree by a nutritional competition effect.

It’s only possible to graft mutually compatible plants. The technique is used for immemorial time in vines and fruit production. It is also used for a long time for some ornamental species such as rose. Since the 50s, it is also used on various annual crops, especially cucurbits such as melon or squash or Solanaceae, such as tomatoes.

A lack of compatibility (also called affinity) will result in a risk of break at the graft union (it is the case of apricot on myrobalan plum), or in a coarse callus reflecting poor vascular communication between rootstock and variety (with usually a poor growth), and in the case of total incompatibility a graft abortion, or rapid death.

 

On the left slide, this peach tree is grafted on a hybrid peach x almond. The graft union is almost perfect. It is barely noticeable, visible only with a slight difference in appearance of the bark, but without any difference in diameter.

In the center, a plum tree grafted on a peach rootstock Monclar ®. Affinity is not perfect. The graft callus is marked. However, the development and behavior of trees is satisfactory. The strength is likely reduced which, in this case, is an advantage.

On the right, a tipical case of poor compatibility. The tree is barely viable. This is an experiment. From 5 trees, this one is the only survivor. It is obvious that this rootstock is not valid for peach tree.

What's the point ?

This technique is primarily used to adapt the crop to the soil on which we will install it. There are resistant rootstocks to calcareous conditions, to water excess sensible soils, to compacted soils, etc. .

Then, it is a contribution to the adaptation of the crop to unfavorable climatic conditions. There is thus rootstocks resistant to drought, which better support cold soils, or on the contrary very high summer heat, or the lack of dormancy in climates like Seville’s one.

It is also a great mean of prophylaxis. That is to say that it is the best way reduce or eliminate the effects of some parasites. The most famous case is the vine, whose European varieties were saved fron phylloxera by grafting method. The great phylloxera crisis began in Europe in 1861, but still remains active in some areas of the world where this aphid has recently arrived on ungrafted vines. In fact the American rootstock used, does not allow the aphid to complete its cycle. It is unable to install. 100% efficiency without any treatment.

Similarly, there are nematode-resistant rootstocks (microscopic worms from the soil, against which available insecticides are  insufficiently active but extremely toxic), others are resistant to certain soil fungi, as phytophthora on citrus, and so on.

Finally, there are purely agronomic criteria, which allow to select a rootstock for its effects on the vigor (the most common case is the apple), on fruit quality, productivity, on the ability of the fruit to conservation.

Each species has a more or less wide range of rootstocks, that allows adapt to diverse culture conditions, according to the place or to the farmer priorities. For example, if a phytosanitary problem such as nematodes is determined or known, it will be the priority, because it may affect the viability of the crop. If there is no imperative of this type, agronomic criteria will logically be the priority.

Attention, we can not do anything. Depending on the conditions, we will be able to adapt a crop through the choice of the rootstock, or not. Insist on planting an inadequate and inadaptable crop is going directly to a technical, so economical failure.

There are a few breeding programs worldwide, to expand the range of rootstocks of different crops. But it is a long and tedious job, which requires many multisite experiments, whose results are slow because it’s necessary to see old culture at least up to the age where it pays the investment. Variety hybridization is much faster and cost effective. The majority of hybridization rootstocks programs are run by public agencies, which do not need to place profitability as a priority. Because if this is the wrong variety, you always can top graft the orchard. It is expensive, but it may be sustained. But if you chose the wrong rootstock, you have to tear all off.

Is it possible to graft anything on anything else?

Of course not. However, there are some compatibility between species, but always within the same genus. One of the most used in pear rootstocks is the quince. In the Prunus family, the intercompatibilities are many, between plum, peach, apricot and almond.

 

On the left slide, a plum variety grafted on peach Monclar®, with good affinity despite the difference in diameter, as the graft callus is perfectly healthy and clean.

On the right, another same aged variety. This is the pollinator of the previous one, on the same rootstock. It is clearly visible that the affinity is reduced, because the graft callus is much bulky, showing a vascular communication of lower quality.

May grafting act on the fruit quality?

Yes, and it is often a criterion of choice of the rootstock. Let’s take the case of apple trees. Most old orchards are grafted onto vigorous rootstocks, which tend to cause a strong tree vigor. Modern orchards are almost always grafted onto rootstocks greatly reducing the vigor, often requiring to stake trees, whose structure (trunk and branches) is not able to support alone the fruit crop without break risk. Debilitating or dwarfing rootstocks generally tend to improve fruit quality and size, provided that the affinity is good, and that culture conditions are appropriate. Indeed, a small tree sends nutrients directly to the fruit, while a vigourous tree directs them to the strongest shoots, also called sucker, to the detriment of fruit.

Techniques and periods for grafting are many, and each crop has its preferences, and each technique has its tricks.

These are very delicate operations requiring proper training and necessary precautions to ensure success.

It is surgery applied to plants.

3- Selection, mutation, breeding, GMOs

After my nervousness last week, I'm going to talk today about a more relaxed (sure?) subject: genetic evolution of species. It is a general subject, valid for both plant and animal species.

What is it?

It’s the various natural or artificial ways that cause the evolution of species. At all times since the invention of agriculture, man has tried to adapt his environment, and his agricultural activities to his needs. He has felt the need to select species for their specific characteristics, thus providing improvements to what had hitherto existed.

1-    SELECTION

It is the most simple process that will be used either alone or in combination to other methods.

It simply consists in observing a population of the same species, and chose the most interesting individuals to use them as parents, so try to transmit to their progeny, characters for which they were identified. For example, in apple, an old and almost extinct variety is Gala, bicolor variety that was achieved around 1920 in New Zealand. It is a variety whose general characteristics are very interesting, but the color does not correspond any more with current standards. In Gala orchards, trees producing the most colorful fruits were selected (in fact they are small natural mutations affecting only the color) to get the current Royal Gala variety. It is the same variety as Gala, but with a more intense red color. We proceed in the same way to select cows producing more milk, sheep producing more wool, running faster horses, or cats or dogs whose characteristics are the taste of the juries of beauty contests.

It is a very old method, which has been all time used by farmers and gardeners around the world, consciously or unconsciously.

2-    MUTATION

This is a natural process, which is a genetic change of one or more characteristics. It is one of the main causes of the evolution of species.

It is a common phenomenon in plants, where you will find in a field either a plant or a branch with different characteristics. Thus it is usual, for example in my peach orchards, find a branch of nectarine, or a twig with fruits of different color or shape. It comes from a genetic change in the formation process of a bud that develops different characteristics. This new feature is set into the genome of the mutant individual or the mutant area and can then be transmitted to its progeny. If the mutant feature is interesting, it may either be used unchanged or it may be used as a parent in order to create a new progeny by a hybridization technique.

It is also possible to cause artificial mutations by controlled irradiation in specialized laboratories.

3-    BREEDING

It is a very old method, based on the observation of characters, and their ability to combine to create a different characteristic. The breeding technique is normally done by natural ways, not allowing the breeding of naturally incompatible individuals. It is currently the main method for getting new varietal characteristics. If you cross a yellow flesh, small and early nectarine, with a late, white and bloody flesh flat peach, you will obtain a wide range of diverse fruit, which will combine in all possible ways, the original characters of parents. We generally consider that, in peach, a controlled crossing of two specific varieties can give a variability of about 500 different types.

It is in this way that, in recent years, appeared in the markets, flat peaches (paraguayo), and flat nectarines (platerines). The origin of the flat character in peach comes from a natural mutation, occurred 2000 years ago in China. Closer to us, there is an old variety, cultivated for many years in the region of Murcia, Spain, called Paraguayo, which is a small flat peach, rather shapeless, greenish, white and bloody flesh, slightly sweet but very aromatic (a type of vineyard peach, green and flat). It was used as parental in several breeding programs, allowing the current varieties diversity.

The technique is simple: you take a tree from a selected variety that will be the female parent (the receiver), and you substitute the natural pollination (normally made ​​by bees) by a delicate fine brushwork, throwing on each flower pistil, pollen grains of the variety chosen as the male parent. It is also possible to proceed by isolating trees of both chosen varieties under a fine mesh net, under which a beehive is placed. Bees have no other choice but to interpollinate the two present trees.

Finally, there is the natural pollination, without human intervention, which simply consists of a carriage of pollen from a variety to the other, done by bees. This technique is not normally used for breeding, but it is widely used for pollination of self-sterile varieties, which means whose pollen is incompatible with its own flower (usual case in apricot, cherry, plum, apple and pear, for example).

Harvested fruits will be the same as the female original variety, because genetic changes are taking place in the seed, thus immediately invisible. It’s necessary to take all seeds and place them to germinate. Each seed has a set of combined characters from both parents.

The two most common breeding types are:

- Intraspecific breeding, which means crossing two varieties (in plants) or two breeds (animals) of the same species. This is for example, crossing a Golden apple with a Granny Smith apple or a German shepherd dog with a boxer dog. In humans, the process is called miscegenation.

- Interspecific breeding, which means crossing two related and compatible species. In plants, it is a cross between wheat and rye (triticale) or clementine and tangerine (clemenvilla) or apricot and plum (aprium or pluot). In animals, there are many cases. The best known is the mule, a cross between horse and donkey, but it is quite common in cats, or in open air pig farms, where sometimes introduce boars.

Remains the problem of F1 hybrids, concerning annual crops seeds. These seeds are produced by first generation artificial pollination whose agronomic characteristics are known, and generally interesting. But the progeny of these F1 hybrids (F2 hybrids) is very different. The farmer is forced to buy seeds every year to maintain the properties of the variety. Seed companies were accused of abusing the system. Although this is partially true (these are for-profit corporations), it should however be said in their defense, that the qualities of F1 hybrids are very difficult to obtain by other ways (stable varieties usually have lower agronomical performance and tend to degenerate over generations), in the other hand, varietal research is very expensive, and it is a way to get the investment back. Seed prices are calculated for mutual profit otherwise seeds companies could not sell anything. Farmers are not stupid, anyway.

4-    GMOs

It is a technique that can be applied both to animals and plants. It consists in the laboratory, to make an artificial modification on a specific gene, to change the behavior of the original organism. The technique allows us to imagine almost any modification or crossing, impossible in nature, especially interspecific crosses, unimaginable by natural ways.

It is obvious that there can be a serious ethical problem using this technique. Moreover, some companies used it as a very powerful economic weapon. It must also be said that the first GMOs varieties, commercialized on a large scale, were for the resistance to herbicides, sometimes causing overconsumption of these herbicides, and environmental problems. Ecologist organizations took it as a symbol of struggle against GMOs, without considering the potential benefits of the method. The anti-globalization organizations, for their part, combined the refusal of GMOs with the fact that these varieties are hybrid F1 too, to violently attack the seed companies, without trying to see the positive aspects of the system. Films have been made on this topic, and political campaigns as well, but without objectivity, playing on the fear of the unknown risk, and using perfectly the power of modern communication. And we know very well, from dictatorships to main political and economic crises, how high is the power of the mass media, and how easy it is to manipulate public opinion by shocking images.

However, it should be noted that this technique allows us to imagine some interesting solutions in specific conditions. For example, there are significant works in progress to create, by this method, crops adapted to saline soils of some regions of the world (and currently prohibiting any type of agriculture), or resistant to severe drought conditions, just to give two examples.

One of the main problems encountered since the first sale of GM crops, is the modification of some proteins in the plant, giving them a sometimes dangerous character to human health. But it seems clear, that if suitable work is done, researchers learn to control these risks. Investigation works are currently in progress in this way.

The technique has probably an important future, in the inevitable goal of feeding the world in the centuries to come, but it is essential to regulate its use.

"Science without conscience is but the ruin of the soul," wrote François Rabelais in 1532 in "Pantagruel". The formula is a bit dated, but it is really current in its meaning. Any new technique can lead to abuses. This is the case with GMOs. The first GM crops have flaws that emerged after their sale. That is not why we must drop the technique, especially because, as it is known, it will inevitably be recovered by not necessarily scrupulous people, who will make it a personal enrichment or domination tool.

However, this technique can provide very interesting answers, to many currently unresolved problems, and for the good of humanity.

It is therefore preferable to continue working on it, to use it in a controlled way, but while establishing the political and legal means to prevent abuses.