Blue tomatoes, also called purple tomatoes, are tomatoes that have been bred to produce high levels of anthocyanins, a class of pigments responsible for the blue and purple colours of many fruits, including blueberries, blackberries and chokeberries. Anthocyanins may provide protection for the plant against insects, diseases, and ultraviolet radiation. Some of these tomatoes have been commercialized under the names "Indigo Rose" and "SunBlack".
While tomatoes have the genes for producing anthocyanins, these genes are typically not expressed in the fruit in most commercial varieties. The result is that the pigments are limited to leaves and stems, where they are not eaten. As of the 2012 growing season, Oregon State University developed blue tomato seeds became commercially available under the cultivar name "Indigo Rose". The blue color is produced mostly by the anthocyanin petunidin on the outside of the tomato where the fruit is exposed to direct sunlight. [1] The shaded side of the fruit is green when unripe, red when ripe, and the inside is red or deep pink. The tomatoes are small, about 2 inches across, round, and grow in clusters of 6 to 8. Flavor is described as slightly acidic. The vines are said to be indeterminate but compact, and disease resistant. While the concentration of anthocyanins is still very low compared to other fruits like blueberries, the pigments do improve the resistance of the fruits to the fungus Botrytis cinerea . [2]
Purple tomatoes have been developed at the John Innes Centre in the UK using genetic modification (GM), incorporating genes from snapdragons to increase the anthocyanin levels in the flesh of the tomatoes. [3] [4] While both the conventionally-bred and the engineered varieties exhibit altered expression of the same transcription factor of the MYB gene class which controls the anthocyanin biosynthesis, the engineered variety additionally produces the pigments in the flesh of the fruit rather than just the skin. [5] This results in almost 100-fold higher concentration of anthocyanins in the engineered fruits compared to the conventional varieties. [6] The inventors of the GM purple tomato, Jonathan D. G. Jones and Cathie Martin of the John Innes Centre, founded a company called Norfolk Plant Sciences to commercialize the purple tomato. [7] [8] In 2014, it was announced that they had partnered with a greenhouse farm in Canada to grow purple tomatoes from which to create new commercial products, [9] but no further announcements were made. In September 2022, the Norfolk Plant Sciences Purple Tomato received USDA approval for distribution in the United States. [10]
Many other tomato cultivars have names indicative of their dark color, such as Black Krim and Cherokee purple. These colours come from an altogether different process, whereby the chlorophyll is not efficiently degraded resulting in the accumulation of the pigment pheophytin in the fruit. [11] This pigment combined with other carotenoids in the fruit, including beta-carotene and lycopene, produces a brown or black color.
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples of berries in the culinary sense are strawberries, raspberries, blueberries, blackberries, white currants, blackcurrants, and redcurrants. In Britain, soft fruit is a horticultural term for such fruits.
Bilberries or blueberries are Eurasian low-growing shrubs in the genus Vaccinium in the flowering plant family Ericaceae that bear edible, dark blue berries. The species most often referred to is Vaccinium myrtillus L., but there are several other closely related species.
The raspberry is the edible fruit of several plant species in the genus Rubus of the rose family, most of which are in the subgenus Idaeobatus. The name also applies to these plants themselves. Raspberries are perennial with woody stems.
Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green, and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make the fruit seem tarter. This effect is attributed to the Brix-Acid Ratio. Climacteric fruits ripen after harvesting and so some fruits for market are picked green.
Chromoplasts are plastids, heterogeneous organelles responsible for pigment synthesis and storage in specific photosynthetic eukaryotes. It is thought that like all other plastids including chloroplasts and leucoplasts they are descended from symbiotic prokaryotes.
Norton is grown in the Midwestern United States, the Mid-Atlantic States, and northeastern Georgia. DNA data are consistent with 'Norton' being a hybrid with ancestry including V. aestivalis and V. vinifera.
Delphinidin is an anthocyanidin, a primary plant pigment, and also an antioxidant. Delphinidin gives blue hues to flowers in the genera Viola and Delphinium. It also gives the blue-red color of the grape variety Cabernet Sauvignon, and can be found in cranberries and Concord grapes as well as pomegranates, and bilberries.
The garden strawberry is a widely grown hybrid species of the genus Fragaria in the rose family, Rosaceae, collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely appreciated for its characteristic aroma, bright red color, juicy texture, and sweetness. It is consumed in large quantities, either fresh or in such prepared foods as jam, juice, pies, ice cream, milkshakes, and chocolates. Artificial strawberry flavorings and aromas are also widely used in products such as confectionery, soap, lip gloss, perfume, and many others.
Vaccinium myrtillus or European blueberry is a holarctic species of shrub with edible fruit of blue color, known by the common names bilberry, blaeberry, wimberry, and whortleberry. It is more precisely called common bilberry or blue whortleberry to distinguish it from other Vaccinium relatives.
Biological pigments, also known simply as pigments or biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan.
Peonidin is an O-methylated anthocyanidin derived from Cyanidin, and a primary plant pigment. Peonidin gives purplish-red hues to flowers such as the peony, from which it takes its name, and roses. It is also present in some blue flowers, such as the morning glory.
Myb genes are part of a large gene family of transcription factors found in animals and plants. In humans, it includes Myb proto-oncogene like 1 and Myb-related protein B in addition to MYB proper. Members of the extended SANT/Myb family also include the SANT domain and other similar all-helical homeobox-like domains.
Pelargonidin is an anthocyanidin, a type of plant pigment producing a characteristic orange color used in food and industrial dyes.
Blueberry is a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section Cyanococcus within the genus Vaccinium. Commercial blueberries—both wild (lowbush) and cultivated (highbush)—are all native to North America. The highbush varieties were introduced into Europe during the 1930s.
Anthocyanins, also called anthocyans, are water-soluble vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart named a chemical compound that gives flowers a blue color, Anthokyan, in his treatise "Die Farben der Blüthen". Food plants rich in anthocyanins include the blueberry, raspberry, black rice, and black soybean, among many others that are red, blue, purple, or black. Some of the colors of autumn leaves are derived from anthocyanins.
Generally, fleshy fruits can be divided into two groups based on the presence or absence of a respiratory increase at the onset of ripening. This respiratory increase—which is preceded, or accompanied, by a rise in ethylene—is called a climacteric, and there are marked differences in the development of climacteric and non-climacteric fruits. Climacteric fruit can be either monocots or dicots and the ripening of these fruits can still be achieved even if the fruit has been harvested at the end of their growth period. Non-climacteric fruits ripen without ethylene and respiration bursts, the ripening process is slower, and for the most part they will not be able to ripen if the fruit is not attached to the parent plant. Examples of climacteric fruits include apples, bananas, melons, apricots, tomatoes, as well as most stone fruits. Non-climacteric fruits on the other hand include citrus fruits, grapes, and strawberries Essentially, a key difference between climacteric and non-climacteric fruits is that climacteric fruits continue to ripen following their harvest, whereas non-climacteric fruits do not. The accumulation of starch over the early stages of climacteric fruit development may be a key issue, as starch can be converted to sugars after harvest.
Myrtillin is an anthocyanin. It is the 3-glucoside of delphinidin. It can be found in all green plants, most abundantly in black beans, blackcurrant, blueberry, huckleberry, bilberry leaves and in various myrtles, roselle plants, and Centella asiatica plant. It is also present in yeast and oatmeal. The sumac fruit's pericarp owes its dark red colour to anthocyanin pigments, of which chrysanthemin, myrtillin and delphinidin have yet been identified.
A genetically modified tomato, or transgenic tomato, is a tomato that has had its genes modified, using genetic engineering. The first trial genetically modified food was a tomato engineered to have a longer shelf life, which was on the market briefly beginning on May 21, 1994. The first direct consumption tomato was approved in Japan in 2021. Primary work is focused on developing tomatoes with new traits like increased resistance to pests or environmental stresses. Other projects aim to enrich tomatoes with substances that may offer health benefits or be more nutritious. As well as aiming to produce novel crops, scientists produce genetically modified tomatoes to understand the function of genes naturally present in tomatoes.
Catherine Rosemary Martin is a Professor of Plant Sciences at the University of East Anglia (UEA) and project leader at the John Innes Centre, Norwich, co-ordinating research into the relationship between diet and health and how crops can be fortified to improve diets and address escalating chronic disease globally.
Orange petunias or A1-DFR petunias are genetically modified organisms which contain a transgene from maize that colors the petunia flowers orange. First created in a 1987 experiment at the Max Planck Institute for Plant Breeding Research in Cologne, the petunias were subsequently released into the wild but were not commercialized. In 2015 orange petunias were discovered in Helsinki by botanist Teemu Teeri, leading to a regulatory response dubbed the petunia carnage of 2017 in which plant sellers were directed to destroy the modified petunia plants rather than sell them. The United States Department of Agriculture approved the sale of orange petunias in the United States in January 2021.