Valorization of Tomato Surplus and Waste Fractions: A Case Study Using Norway, Belgium, Poland, and Turkey as Examples

Abstract

There is a large potential in Europe for valorization in the vegetable food supply chain.
For example, there is occasionally overproduction of tomatoes for fresh consumption, and a fraction of the production is unsuited for fresh consumption sale (unacceptable color, shape, maturity, lesions, etc.). In countries where the facilities and infrastructure for tomato processing is lacking, these tomatoes are normally destroyed, used as landfilling or animal feed, and represent an economic loss for producers and negative environmental impact. Likewise, there is also a potential in the tomato processing industry to valorize side streams and reduce waste. The present paper provides an overview of tomato production in Europe and the strategies employed for processing and valorization of tomato side streams and waste fractions. Special emphasis is put on the four
tomato-producing countries Norway, Belgium, Poland, and Turkey. These countries are very different regards for example their climatic preconditions for tomato production and volumes produced, and represent the extremes among European tomato producing countries. Postharvest treatments and applications for optimized harvest time and improved storage for premium raw material quality are discussed, as well as novel, sustainable processing technologies for minimum waste and side stream valorization. Preservation and enrichment of lycopene, the primary health promoting agent and sales argument, is reviewed in detail. The European volume of tomato postharvest wastage is estimated at >3 million metric tons per year. Together, the optimization of harvesting time and preprocessing storage conditions and sustainable food processing technologies,
coupled with stabilization and valorization of processing by-products and side streams, can significantly contribute to the valorization of this underutilized biomass

Full text

Foods 2019, 8, 229; doi:10.3390/foods8070229 www.mdpi.com/journal/foods
Article
Valorization of Tomato Surplus and Waste Fractions:
A Case Study Using Norway, Belgium, Poland, and
Turkey as Examples
Trond Løvdal
1,
*, Bart Van Droogenbroeck
2
, Evren Caglar Eroglu
3
, Stanislaw Kaniszewski
4
,
Giovanni Agati
5
, Michel Verheul
6
and Dagbjørn Skipnes
1
1
Department of Process Technology, Nofima – Norwegian Institute of Food, Fisheries and Aquaculture
Research, N-4068 Stavanger, Norway; dagbjorn.skipnes@nofima.no
2
ILVO – Institute for Agricultural and Fisheries Research, Technology and Food Science Unit,
9090 Melle, Belgium; Bart.VanDroogenbroeck@ilvo.vlaanderen.be
3
Department of Food Technology, Alata Horticultural Research Institute, 33740 Mersin, Turkey;
evcager@gmail.com
4
Department of Soil Science and Vegetable Cultivation, InHort – Research Institute of Horticulture,
96-100 Skierniewice, Poland; stanislaw.kaniszewski@inhort.pl
5
Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata ‘Nello Carrara’,
50019 Sesto Fiorentino, Italy; g.agati@ifac.cnr.it
6
NIBIO – Norwegian Institute of Bioeconomy Research, N-4353 Klepp Stasjon, Norway;
michel.verheul@nibio.no
* Correspondence: trond.lovdal@nofima.no
Received: 1 June 2019; Accepted: 24 June 2019; Published: 27 June 2019
Abstract: There is a large potential in Europe for valorization in the vegetable food supply chain.
For example, there is occasionally overproduction of tomatoes for fresh consumption, and a fraction
of the production is unsuited for fresh consumption sale (unacceptable color, shape, maturity,
lesions, etc.). In countries where the facilities and infrastructure for tomato processing is lacking,
these tomatoes are normally destroyed, used as landfilling or animal feed, and represent an
economic loss for producers and negative environmental impact. Likewise, there is also a potential
in the tomato processing industry to valorize side streams and reduce waste. The present paper
provides an overview of tomato production in Europe and the strategies employed for processing
and valorization of tomato side streams and waste fractions. Special emphasis is put on the four
tomato-producing countries Norway, Belgium, Poland, and Turkey. These countries are very
different regards for example their climatic preconditions for tomato production and volumes
produced, and represent the extremes among European tomato producing countries. Postharvest
treatments and applications for optimized harvest time and improved storage for premium raw
material quality are discussed, as well as novel, sustainable processing technologies for minimum
waste and side stream valorization. Preservation and enrichment of lycopene, the primary health
promoting agent and sales argument, is reviewed in detail. The European volume of tomato
postharvest wastage is estimated at >3 million metric tons per year. Together, the optimization of
harvesting time and preprocessing storage conditions and sustainable food processing technologies,
coupled with stabilization and valorization of processing by-products and side streams, can
significantly contribute to the valorization of this underutilized biomass.
Keywords: tomato; valorization; sustainable production; processing; lycopene; waste reduction;
vegetables; postharvest physiology; healthy food
1. Introduction

Foods 2019, 8, 229 2 of 21
The tomato (Solanum lycopersicum (L.)), which is neither a vegetable nor a fruit but botanically
speaking a berry, is currently spread across the world and is a key element in most cultures cuisines.
The tomato originated in South America, from where it was imported to Mexico. Tomato came to
Europe from the Spanish colonies in the 1500s along with several other “new” plants such as maize,
potato, and tobacco. The tomato plant was immediately cultivated in the Mediterranean countries,
but was initially poorly received further north in Europe. The skepticism of the tomato was due to
that it was long suspected to be poisonous. As a curiosity, the tomato was not found in Norwegian
grocery shelves until well into the 1950s, and was thus more exotic than oranges and bananas.
Nowadays, however, tomatoes have definitely become an essential ingredient also in the North
European and the Nordic cuisine. For example, in Norway, tomatoes have in recent years been the
most sold product in the fresh vegetable segment, with a total turnover of approximately 15 million
€ and an annual consumption of 7.3 kg per capita, of which 1/3 is produced in Norway [1]. Including
also processed tomato products, annual per capita consumption in Norway increases to 16.3 kg,
whereas it is 23.5 and 27.5 kg in Poland and Belgium, respectively. These are however still low values
compared to the Mediterranean diet; annual per capita consumption in Turkey, Armenia, and Greece
is 94, 85, and 77 kg, respectively, whereas in Italy, Spain, Portugal, and Ukraine it is approximately
40 kg [2]. For a detailed list of European tomato production and consumption, see Supplementary
Table S1.
A joint FAO/WHO Expert Consultation report on diet, nutrition and the prevention of chronic
diseases, recommended several years ago the intake of a minimum of 400 g of fruit and vegetables
per day (excluding potatoes and other starchy tubers), for the prevention of chronic diseases such as
cardiovascular diseases (CVD), diabetes, and obesity, as well as for the prevention and alleviation of
several micronutrient deficiencies [3]. However, in the western world, the consumption of vegetables
is still far less than recommended. There is thus a socioeconomic gain if one succeeds in stimulating
increased consumption of tomato-based products high in lycopene and β-carotene that may lead to
reduced incidents of cancers and CVD. To increase the consumption of vegetables, it is important to
provide raw materials with high quality, diversity, and availability. Fruit and vegetables are
important components of a healthy diet, and their sufficient daily consumption could help prevent
major diseases such as CVD and certain cancers. According to the World Health Report 2002, low
fruit and vegetable intake is estimated to cause ~31% of ischemic heart disease and 11% of stroke
worldwide [4]. Overall, it is estimated that up to 2.7 million lives could potentially be saved each year
if fruit and vegetable consumption were sufficiently increased.
There is a large potential in Europe for optimization in valorization of crop biomass in the
vegetable food supply chain. For example, there is occasionally overproduction of tomatoes for fresh
consumption, and a fraction of the production is unsuited for fresh consumption sale (unacceptable
color, shape, maturity, lesions, etc.). These tomatoes are normally destroyed and used as landfilling
or animal feed, which represents an economic loss for producers and negative environmental impact.
In Norway and Belgium, this surplus/waste fraction amounts to about 200 (Unpublished data from
Rennesøy Tomat & Fruktpakkeri AS (2012), the biggest tomato packaging station in Norway) and
500 tons per year [5], respectively. A conservative estimate of € 4 per kg price increase for this raw
material will thus yield a potential of 0.8 and 2.0 million € per year, respectively, for Norway and
Belgium alone. Besides overproduction, part of the tomatoes produced in the greenhouse might not
reach the market because they do not reach the local market standards. This can be due to cosmetic
defects such as color, shape, size, etc.
Additionally, there is loss of fresh tomato at the retailer’s level. In Norway, the general retailer
loss is 10% for cluster tomatoes, 3–6% for single retail (“ordinary round”) tomatoes, and
approximately 1% for cherry tomatoes, but it can be substantially higher in the peak of the growing
season [6]. In the case of Norway, assuming a mean loss at retailers level of 5%, and that this loss can
be halved by improved market regulation, there is a value increasing potential of a further 0.8 million
€ per year, again with a conservative price estimate of € 4 per kg. It is assumed that the total loss
fraction is approximately the same in the other European countries, implying a much higher value
potential in countries producing more tomatoes than Norway, considering that Norway is indeed a

Foods 2019, 8, 229 3 of 21
small tomato producer by European standards (Supplementary Table S1). An estimate for the total
European market, based on a total waste fraction assuming a 15% waste in the tomato processing
industry (including what is left in the field), and 5% waste in fresh market tomato, the waste fraction
amounts to 3 million metric tons per year (Supplementary Table S1). The tomato processing waste
quantities worldwide in 2010 was estimated to be between 4.3 and 10.2 million metric tons [7]. Based
on this, it is beneficial to develop processing technology for the best possible utilization of this
resource to improve economic sustainability of tomato production.
2. Tomato Production in Norway, Belgium, Poland and Turkey
2.1. Norway
Tomato production in Norway has been stable for the last 15 years with volumes between 9000
and 12,000 tons per year. Ninety percent of the production takes place in the county of Rogaland, on
the southwest coast. Practically all tomatoes produced in Norway are destined for the domestic fresh
market. The production is costly because the Norwegian climate necessitates the use of heated glass
houses and artificial light for year-round production. Because of the high production costs,
Norwegian tomatoes have traditionally not been subject to processing. Recently, some tomato
farmers have found ways to alleviate the energy expenses by innovative solutions. One example of
this is the ‘Miljøgartneriet’ which can be translated as ‘the Environmental plant nursery’ [8]. This
glass house was built in 2010, covers 77 000 m2, and employs 70–85 workers in the high season. The
innovations consist of amongst others the use of surplus CO2 and warm wastewater from a nearby
dairy plant for plant feed and heating, respectively. Combined with other energy-efficient solutions
in the construction of the glass house and recirculation of water, the production becomes more
sustainable and with a low carbon footprint. An optimized year-round cultivation system achieved
a yield of over 100 kg m−2 in commercial production, with an estimated maximum potential of
125–140 kg m−2 [9]. In Norway, the surplus fraction resulting from high-season overproduction
amounts to 200 tons per year, corresponding to approximately 2% of total production. Total waste,
i.e., combined with the waste at the retailer level and in the greenhouses, is estimated at ~6%. One of
the main reasons for waste at the retailer level was found to be due to packaging. Comparing
packaged cluster tomatoes to loose, unpacked single tomatoes revealed, contrary to expectation, that
the former had significantly more wastage [6]. It was speculated that this was because packaging may
lead to condensation and subsequent growth of molds. Therefore, packaging of warm tomatoes
should be avoided [6]. Temperature abuse during transport and in the stores was also considered as
main factors leading to waste [6].
Efforts have been made to produce tomato sauce of the surplus tomatoes. However, due to small
volumes and high production costs, this turned out not to be economically viable and production
stopped. At present, the fraction is primarily used as cattle feed, so that costs for disposal can be
minimized. In order to overcome the seasonality problem, tomato surplus and waste fractions may
be sorted and stored frozen in order to collect volumes for subsequent processing and perhaps to add
this to batches of imported tomatoes for processing. A project is now starting up in Norway to look
into this possibility for valorization and to identify and overcome the challenges related to this
strategy.
2.2. Belgium
Belgian tomato production takes predominantly place in Flanders, where some 250 growers
produced 220 to 260,000 tons per year on about 500 hectares between 2006 and 2016. Tomato is the
second biggest crop under glass after lettuce, but generates the biggest economic return, ~180 million
€ per year, leaving the second and third place to strawberry and bell pepper, respectively. Belgian
tomato growers deliver tomatoes for the internal fresh market during a period of about nine months
each year. There are three areas in Flanders where the tomato growers cluster together, that is around
Mechelen, Hoogstraten, and Roeselare. Roughly, half of the production is on the vine and the other
half are loose tomatoes [10]. Also in Belgium, practically all tomatoes are produced in greenhouses

Foods 2019, 8, 229 4 of 21
and for fresh consumption. The average price the growers get for their tomatoes (loose and on the
vine) is about € 0.75 per kg. As opposed to Norway, Belgian tomato export volumes are considerable.
Today, approximately 70% of all tomatoes produced in Belgium are exported [10]. According to Lava,
the cooperative of all Belgian fruit and vegetable auctions, the main exporting partners are France,
Germany, the Netherlands, the UK, and the Czech Republic [11]. The tomato surplus fraction in
Belgium makes up about 500 tons per year, corresponding to approximately 2% [5], as in Norway,
and total waste (retailers, etc.) is estimated at approximately 5%. A recent study in Belgium estimated
the losses of tomato that cannot be marketed due to cosmetic reasons to be ~1–2% only. Similar
numbers were recorded for bell pepper and cucumber. This is very low compared to the percentages
of other crops (e.g., zucchini 11.5% and lettuce 9.1%) [12].
2.3. Poland
Polish tomato production is different from Norwegian and Belgian production in several ways.
First, the polish production volume is 3 times the Belgian and >60 times the Norwegian with a yearly
production amounting to ~920,000 tons (~250,000 tons in the field and ~670,000 tons in greenhouses)
[13], placing them among the top eight in Europe (Supplementary Table S1). Moreover, the
production is carried out both in open field and under cover. The cultivation area under cover is
approximately 27% of the total, but it is increasing [14]. Approximately 70% of the production takes
place in Greater Poland, Kuyaivan-Pomeranian, Mazovian, and Switokrzyskie Provinces. Since
Poland’s entry into the EU in 2004, fresh tomato exports have doubled, and accounts now for about
11% of production [14]. Approximately 1/3 of the total production is processed domestically, mainly
into tomato paste and canned tomatoes (approximately 40,000 tons per year), and ketchup and
tomato sauce (approximately 135,000 tons per year), whereof ~50% are exported [13]. The production
of greenhouse tomatoes is intended for the fresh market and nearly 80% of production is sold on the
internal market. The remaining 20% is export, and the main recipients are Ukraine, Belarus, the Czech
Republic, Germany and the United Kingdom. The processing waste value can be assumed to be up
to approximately 8.5%. This value consists of 1–3% seed waste, 2.8–3.5% skin, and up to 2% as whole
fruit waste. Measures to reduce losses like choosing correct harvest time, avoiding damage during
harvest, storage of crops protected from sunlight and immediate cool storage, the removal of
damaged fruit, and using clean packaging material and proper transport are also important in
Poland. The results obtained in open field tomato production in Poland depend very much on
weather conditions. In some years, maturation is delayed and the quality of the fruits is poor, and it
is very important to protect plants from diseases. These detrimental effects can be increased through
improper nitrogen fertilization, which can delay the maturity of the fruits. In addition, the growing
seas on in s ome y ears may be shorter due to the occurr ence of ear ly au tumn frosts. In the se conditions,
unripen tomato fruits remain in the field and is lost. To reduce losses, proper nitrogen fertilization,
early varieties with concentrated fruiting, and the use of ethylene to accelerate ripening are proposed.
2.4. Turkey
Turkey is the fourth largest tomato producer after China, India and the United States, yielding
more than 7.2% of the world tomato production. The production amount was ~11.8 million tons in
2014 and 12.7 million tons in 2017. Sixty-seven percent of total production was evaluated as table
tomato and 33% were industrially processed. More than 25% of the total production and 40% of table
tomato is cultivated in greenhouses. Three-and-a-half-million tons (~28%) of the tomato production
is being processed into paste, while 500,000 tons (4%) is used as sun-dried and canned (whole peeled,
cubic chopped, puree, etc.). Due to the climate advantage, sun-dried tomatoes have great potential
and almost all (97%) of them are exported. Tomato is the undisputed and clear leader product of the
vegetable industry in Turkey. Tomato export is almost 40% of total fresh vegetable exportation of
Turkey. From 10 to 18% of the total processing raw material is gone to waste [15]. Skin, seeds, fiber,
etc. make up ~7% of this fraction, and the rest is mainly due to bad transportation in the tomato paste
industry. Between 2010 and 2017, the average losses during harvesting were 3.5% and loss after
harvesting was 10 to 15%. In 2017, pre- and postharvest losses were more than 2.1 million metric tons,

Foods 2019, 8, 229 5 of 21
corresponding to 16.5% of the total production [16]. Occurrences of exceptional high tomato wastage
of up to 28% in specific regions have been reported [17]. Measures to reduce losses are summarized
as choosing correct harvest time, avoiding damage during harvest, storage of crops protected from
sunlight and immediate cool storage, the removal of damaged fruit, and using clean packaging
material and proper transport [18]. The following precautions were proposed in order to reduce loss
between harvesting and processing or wholesale: Choosing an earlier harvest time, using better
packaging material at the farm stage instead of only traditional wooden or plastic cases, and
refrigerated transport to the packaging or processing facilities [19].
3. The Significance of Lycopene in Tomato
Consumers are increasingly demanding naturally nutritious and healthy products that are
produced without the use of genetic modification or additives and pesticide residues. It is therefore
a large potential for developing processed products based on the part of the tomato production that
does not go to fresh consumption. It turns out that the willingness to pay among the modern
consumer increases when positive health effects attributed to the products can be documented. Most
of the adult consumers are aware of the health benefits attributed to lycopene and other
phytonutrients found in tomato, and thus lycopene is the second most important driver for consumer
preferences, after price [20].
Lycopene is a member of the carotenoid family of compounds and is a key intermediate in the
biosynthesis of many carotenoids. Lycopene is a pigment found in small amounts in many fruits and
vegetables, and which, like carotene, gives rise to red color. Tomatoes are the main source of
lycopene, while chili peppers may contain comparable amounts, and watermelon, red bell pepper,
carrot, spinach, guava, papaya, and grapefruit contain relatively moderate amounts [21,22].
Lycopene occurs in several forms (isomers), some of which are taken up more easily by the human
body than others [22–24]. The all-trans form is predominating in fresh tomato (~90%) [25], whereas it
is the cis isomer that is most easily bioavailable to the human body [26–28]. Besides being an
important nutrient, lycopene is also a very potent and sought after natural colorant with many
applications in industrial food processing [29].
Research has shown that by means of processing it is possible to increase the proportion of the
most bioavailable forms and stabilize these to thereby provide an increased health benefit. There is
evidence that heat treatment and the addition of vegetable oils in tomato products increases the
body's absorption of lycopene compared with corresponding consumption of fresh tomato [25,27,30].
For lycopene to be absorbed in the duodenum, it must be dissolved in fat. The fat should not contain
components which compete with lycopene for absorbing, such as vitamin E and K [25,31]. Although
the biochemical mechanisms that make lycopene so beneficial to health are largely unknown, there
is much to suggest that antioxidant and provitamin A properties can be crucial.
3.1. Lycopene Content in Tomato
The lycopene range (0.03–20.2 mg/100 g) as reviewed in Table 1 is comparable to original results
presented by Adalid et al. [32] where 49 diverse accessions of tomato from 24 countries on four
continents displayed a span from 0.04 to 27.0 mg lycopene/100 g. In some wild species of tomato
(S. pimpinellifolium), the lycopene concentration can be as high as 40 mg/100 g [33]. As shown in Table 1,
the type and variety of tomato is also crucial for lycopene. Even the origin and the geographic location
of their cultivation appears to play a major role [34,35]. This is probably due to different growing
conditions and the degree of maturity [36,37], storage and transport conditions, etc.
Table 1. Lycopene content in tomato varieties (converted to mg/100 g fresh weight (FW)). Literature
review. Values in italics are obtained by spectrophotometry, otherwise high-performance liquid
chromatography (HPLC).
Variety Total
Lycopene Type Origin Growth Conditions Reference
Ministar 3.11 plum SW Norway Greenhouse, soil free

Foods 2019, 8, 229 6 of 21
Juanita 10.51 cherry
This
study
Dometica 4.08 salad
Volna 8.15 salad Skierniewice,
Poland Field
Calista 10.75 processing
Pearson 10.77 N/A California, USA Field [38]
DX-54 ~12 N/A Utah, USA Field [39]
Unknown 15.8 N/A Florida, USA Unknown [40]
Amico 7.73
processing
Gödöllö,
Hungary
Field [41]
Casper 6.61
Góbé 5.92
Ispana 6.22
Pollux 5.14
Soprano 8.65
Tenger 7.66
Uno 7.09
Zaphyre 6.95
Draco 6.87
Jovanna 11.61
K-541 9.95
Nivo 8.46
Simeone 9.88
Sixtina 10.51
Monika 7.22
salad
Delfine 6.51
Marlyn 5.53
Fanny 5.26
Tiffany 6.23
Alambra 5.40
Regulus 6.59
Petula 6.68
Diamina 6.48
Brillante 8.47
Furone 5.18
Linda 5.69
Early Fire 10.1–14.0
processing Field [42]
Bonus 8.5–12.7
Falcorosso 8.0–11.1
Korall 8.1–11.3
Nívó 9.7–15.5
Strombolino 5.3–10.3 cherry, processing Gödöllö,
Hungary Field [43]
12 unnamed local
varieties 5.04–13.46 N/A
SE Spain Field [44] ACE 55 VF 6.38 Flattened globe
Marglobe 8.46 Round
Marmande 7.01 Flattened globe
CIDA-62 6.23 cherry
Spain Organic, field [45]
CIDA-44A 2.95
round CIDA-59A 2.70
BGV-004123 5.50
BGV-001020 3.66 flattened and ribbed
Baghera 4.64 round
CXD277 15.33
processing Spain Field [46]
H9661 12.21
H9997 14.96
H9036 11.36
ISI-24424 17.01
Kalvert 16.71
Kalvert 20.2 processing Lecce, Italy Field [47]

Foods 2019, 8, 229 7 of 21
Hly18 19.5
Donald 9.5
Incas 9.3
143 9.47
N/A San Marzano,
Italy Field [48]
Stevens 10.2
Poly20 16.0
Ontario 6.54
Sel6 9.73
Poly56 14.2
1447 5.61
977 10.0
1513 9.21
988 14.1
Cayambe 13.5
Heline 9.46
1512 3.25
1438 6.35
Motelle 16.9
Momor 13.3
981 2.33
Poly27 11.0
Shasta 6.7–7.7
Early-season varieties
California, USA Field [49]
H9888 8.9–9.7
Apt410 9.1–10.0
CXD179 9.2–10.4
Mid-season varieties CXD254 10.5–12.0
H8892 8.7–10.1
CXD222 9.8–13.2
Late-season varieties H9665 8.7–12.2
H9780 9.2–13.0
Bos3155 14.92
Red varieties
California, USA Field [50]
CXD510 15.37
CXD514 11.80
CXD276 2.47
Light color Tangerine
variety
CX8400 0.08 Yellow variety
CX8401 0.68 Orange variety
CX8402 0.03 Green variety
SEL-7 3.23 N/A Haryana, India [51]
ARTH-3 4.03
Laura 12.20 N/A New Jersey,
USA Greenhouse [52]
Brigade 12.9 Processing
Salerno, Italy N/A [53]
PC 30956 18.7 High lycopene
experimental hybrid,
Cheers 3.7 N/A Southern France Greenhouse [54]
Lemance 3.7–6.9 N/A N/A Greenhouse [36]
Ohio-8245 9.93
Tomato pulp fraction Ontario, Canada N/A [55]
92-7136 7.76
92-7025 6.46
H-9035 10.19
CC-164 10.70
Dasher 3.98
Plum Italy Greenhouse [56]
Iride 4.45
Navidad 4.89
Sabor 5.22
292 4.57
738 4.77
Cherubino 3.43 Cherry

Foods 2019, 8, 229 8 of 21
Crimson, green, 0.52
Salad Ohio, USA
Purchased from local
market [57]
Crimson, breaker 3.84
Crimson, red 5.09
Unknown 10.14 Cherry
California, USA Purchased from local
supermarket [58] Unknown 5.98 On-the-vine
Roma 8.98 Processing
Jennita 1.60–5.54 Cherry SW Norway Greenhouse, soil free [59] a
Naomi 7.1–12.0 Cherry Sicily, Italy Cold greenhouse [60] b
Naomi 12.4–13.3 Cherry
Italy Cold greenhouse [34] Ikram 8.5–8.9 Cluster
Eroe 2.1–2.8 Salad
Corbarino 6.8–14.6 Cherry Battipaglia, Italy Field grown [61]
c
(a) Harvested twice monthly from May to October. (b) Harvested at six different times throughout
the year. (c) As an effect of N and P fertilization load; Values in italics are obtained by
spectrophotometry, otherwise high-performance liquid chromatography (HPLC)
It is well known that tomato lycopene is concentrated in the skin and the water-insoluble fraction
directly beneath the skin [53]. Table 2 demonstrates this partitioning and underpins that the tomato
skin waste fractions is a good source of lycopene. Since lycopene and other carotenoids are most
concentrated in and just inside the skin, lycopene is often higher per volume in small tomatoes of
cherry type, because they have a relatively high peel to volume ratio.
Table 2. Lycopene content in peel versus pulp in some tomato varieties (converted to mg/100 g FW).
Literature review. Values in italics are obtained by spectrophotometry, otherwise HPLC.
Cultivar
Total Lycopene
(Converted to mg/100 g FW) Comment Reference
Peel Pulp
HLT-F61 89.3 28.0
Field grown, Northern Tunisia [62]
HLT-F62 50.8 16.7
Rio Grande 42.4 10.1
8-2-1-2-5 14.3 6.7
Harvested at mature green stage (Ludhiana,
India) and stored at 20 °C until ripe [37]
Castle Rock 13.1 6.2
IPA3 10.2 4.0
Pb Chhuhra 8.6 4.6
UC-828 6.5 3.7
WIR 4285 6.5 3.1
WIR-4329 8.1 4.3
818 cherry 14.1 6.9
Field grown, New Delhi, India [63]
DT-2 8.1 5.2
BR-124 cherry 10.2 4.9
5656 10.7 4.5
7711 9.0 4.4
Rasmi 10.8 4.3
Pusa Gaurav 10.2 4.0
T56 cherry 12.0 3.8
DTH-7 4.8 2.7
FA-180 7.6 2.5
FA-574 6.1 2.2
R-144 6.2 2.0
Grapolo 6.0 1.2
Purchased in supermarket or open-air
market, Zagreb, Croatia, [64]
Italian cherry
tomato 7.2 2.0
Croatian cherry
tomato 5.3 1.6
Croatian large size
tomato 3.5 1.3

Foods 2019, 8, 229 9 of 21
Turkish large size
tomato 3.3 1.2
FW: fresh weight. Values in italics are obtained by spectrophotometry, otherwise high-performance
liquid chromatography (HPLC).
Since lycopene is the pigment responsible of the red hue of tomatoes, it can be derived that
unripe tomatoes and light color tangerine varieties and green, orange and yellow varieties are lower
in lycopene than mature red tomatoes [47,62]. Tomatoes with lower lycopene can be stored under
special light and temperature so that they may accumulate lycopene before processing. Figure 1
illustrates the correlation between maturity stage, color, and lycopene content.
Figure 1. Lycopene evolution in processing tomatoes, cv. Calista, as measured during ripening in the
field by a nondestructive optical method as previously described in Ciaccheri et al., 2019 [65].
FW: fresh weight.
Sikorska-Zimny et al., 2019 [66] proposed that, although tomatoes harvested at the full-ripe stage
maintained 90% of their lycopene content for three weeks of storage, a compromise between firmness
and storability may be found by harvesting at an earlier stage in order to balance the organoleptic
and nutraceutical quality of the fruit. This means, at least for fresh-market tomatoes, that they can be
harvested un-ripe in order to obtain storability without compromising neither on sensory or
nutraceutical qualities, as long as proper storage conditions are obtained.
3.2. Effect of Processing
Processing strategies for tomatoes range from the very simple, as for fresh-market tomatoes, to
complicated, as for the production of, e.g., tomato paste which includes multiple steps and several
heat treatments such as drying, hot-break, and pasteurization [67]. Conclusions in relation to
lycopene are that it is only slowly broken down by boiling (100 °C), and therefore constitutes no
restriction for the heat treatment (Table 3) [67–71]. On the contrary, boiling for around two hours
results in breakdown of carotenoid-associated protein structures so that lycopene is released,
isomerization occurs and bioavailability increases [69,72]. Interestingly, Seybold et al., 2004 [70]
found that lycopene isomerization occurred readily as an effect of thermal treatment in a standard
lycopene solution, but this was not the case in tomatoes treated at the similar time/temperature
conditions. Nevertheless, in freeze-dried lycopene powder, it was found that high temperatures (120

Foods 2019, 8, 229 10 of 21
°C) and relatively short exposure time resulted in profound isomerization in both water and oil
medium, but that loss of lycopene was significantly less in oil medium, presumably because oxidation
was avoided [73,74]. Effects of thermal treatment on a range of health-beneficial antioxidants in
tomato are reviewed in Capanoglu et al., 2010 [67], and it may seem that most of the other
antioxidants (e.g., vitamin C and tocopherols, phenolics and flavonoids) are less heat-stable than
lycopene. Mechanical and thermal treatment have significant effects on the consistency of tomatoes,
the former mainly due to the release of pectin [75]. Mechanical treatment does not seem to affect the
content of lycopene to any significant degree, but it may enhance bioavailability, especially when
combined with thermal treatment [75]. Factors such as light, pH, and temperature is very critical to
the stability of lycopene and carotenes [76]. Wrong processing or storage (i.e., exposure to light and
oxygen) may, therefore, affect the ratio between isomers or totally degrade the beneficial compounds.
However, when optimal storage criteria are met, lycopene is a very stable molecule [77]. Traditional
processing methods have only little effect on the level of lycopene or isomerization [25]. In fact,
thermal processing may generally increase the bioavailability of lycopene despite decrease of the total
concentration of lycopene [27,57]. Studies that have followed the evolution of lycopene through the
different processing steps of commercial tomato paste production are inconclusive, either reporting
a small increase [41] or a significant decrease [78] as the tomatoes are processed into paste. Comparing
rapid industrial scale continuous flow microwave pasteurization to conventional thermal processing
of tomato juice, revealed that this novel energy-efficient technology resulted in a product with a
higher antioxidant capacity and similar organoleptic, physiochemical and microbiological qualities
[79]. High pressure processing (HPP) may increase lycopene extractability compared to conventional
processing and result in higher carotenoid content, including lycopene, in tomato purées [80,81]. HPP
also results in less lycopene cis-isomers compared to thermal processing [82].
Table 3. Effects of heat treatment on tomato products.
Processing Heat treatment Effect Texture Taste Lycopene Color
Chopping raw
Mild < 80 °C
Enzymes are released,
pectin degraded and
hexanal/hexanol formed
Thick before
heating, then soup
Vivid
Green Unchanged
Poor,
controlled
by pH
Strong > 80 °C Moderate
green Increased Acceptable
Chopping raw,
waiting for thickening
before cooking, for
example 2 h
Instantly to 100
°C, medium
shortly, to
thicken
Slightly thick and
thickens with
increased cooking
time
Vivid
Green
Somewhat
increased Acceptable
Chopping cooked
Mild < 80 °C Enzymes inactivated only
partially Thin Moderate
green Unchanged
Poor,
controlled
by pH
Strong > 80 °C Enzymes inactivated Thick Green
aroma Unknown Acceptable
Puree, unpeeled
2 h 100 °C
Carotenoid content
maximum after 2 h.
Unknown A little
green
Most after 2 h * Most after
2 h
Puree, peeled
Carotenoid content low
and stable unaffected by
time
Less than
unpeeled
Less than
unpeeled
* Carotenoid associated protein structures are broken down so that lycopene is released and
isomerization occurs so that the bioavailability increases.
Regarding lycopene and processing, the challenge is to limit the breakdown and stimulate the
desired isomerization. In order to optimize the contents of isomerized lycopene, the kinetics of both
isomerization and breakdown have to be known for the specific process. Experiments including a
high number of time/temperature combinations should be done for a number of situations, e.g.,
aerobe vs. anaerobe processing and at different pH. It is only highly concentrated (e.g., dried powder)

Foods 2019, 8, 229 11 of 21
and, to a certain extent, concentrated and sterilized (canned) products that generally exhibit enlarged
lycopene concentration compared to fresh tomato (Tables 4 and 5). However, a heavy heat treatment
is very energy intensive, and often leads to undesirable sensory properties.
Table 4. Lycopene content in tomato products (converted to mg/100 g FW). Literature review. Values
in italics are obtained by spectrophotometry, otherwise HPLC.
Product Total lycopene Comment Reference
Pulp 10.6–18.7
Commercial products, Salerno, Italy [53]
Purée 12.7–19.6
Paste 57.87
Commercial products, California, USA [58]
Purée 23.46
Juice 10.33
Ketchup 12.26–14.69
Juice, heat concentrated 2.34 Experimentally processed from Crimson-type
tomatoes purchased from local markets, Ohio,
USA
[57]
Paste, heat concentrated 9.93
Soup, retorted 10.72
Sauce, retorted 10.22
Juice 7.83
Experimentally processed from tomatoes
purchased from local markets and heat treated
according to standardized industrial food
processing requirements
[25]
Soup, condensed 7.99
Canned whole tomato 11.21
Canned pizza sauce 12.71
Paste 30.07
Powder, spray dried 126.49
Powder, sun dried 112.63
Sun dried in oil 46.50
Ketchup 13.44
Tangerine tomato sauce 4.86 Experimentally processed from tomatoes grown at
the Ohio State University, USA [30] Tangerine tomato juice 2.19
Red tomato juice 7.63
Regular salad tomatoes,
Gran Canaria , Spain
1.15 Fresh
[69]
1.09 Boiled 10 min
0.99–1.18 LTLT, 60 °C 40 min
1.07–1.23 HTST, 90 °C 4 min
Bella Donna on the vine,
Netherlands
3.80 Fresh
3.06 Boiled 20 min
3.91–4.31 LTLT, 60 °C 40 min
3.43–4.15 HTST, 90 °C 10 min
Daniella, Spain 2.37 Fresh purée [81]
Daniella, Spain
0.99 Fresh
[80]
1.48 HP (400 MPa, 25 °C, 15 min)
0.86 Pasteurization (70 °C, 30 s)
0.95 Pasteurization (90 °C, 60 s)
Torrito, Spain
39.67 Fresh
This study
26.39 HTST (90 °C, 15 min)
23.77 HP (400 MPa, 90 °C, 15 min)
Torrito, the Netherlands
11.44 Fresh
7.57 HTST (90 °C, 15 min)
10.10 HP (400 MPa, 90 °C, 15 min)
10.00 HP (400 MPa, 20 °C, 15 min)
5.41 HP (600 MPa, 90 °C, 15 min)
4.08 HP(600 MPa, 20 °C, 15 min)
Heinz purée, USA
6.62 Puré, fresh
[83]
6.61 Boiled 5 min
6.57 Boiled 10 min
6.48 Boiled 30 min
6.39 Boiled 60 min
Double concentrated
commercial canned
39 Unheated [68]
31 Autoclaved 100 °C, 20 min

Foods 2019, 8, 229 12 of 21
tomato purée,
Netherlands
29 Autoclaved 100 °C, 60 min
29 Autoclaved 100 °C, 120 min
28 Autoclaved 120 °C, 20 min
30 Autoclaved 120 °C, 60 min
29 Autoclaved 120 °C, 120 min
31 Autoclaved 135 °C, 20 min
33 Autoclaved 135 °C, 60 min
32 Autoclaved 135 °C, 120 min
Experimental purée
3.79 Unheated
[84]
5.93 Steam retorted, 90 °C, 110 min
5.20 Steam retorted, 100 °C, 11 min
4.74 Steam retorted, 110 °C, 1.1 min
3.37 Steam retorted, 120 °C, 0.11 min
FG99-218, USA
16.04 Juice, fresh
[85]
16.05 Juice, hot break
17.95 Juice, HP (700 Mpa/45 °C/10 min)
17.12 Juice, HP (600 Mpa/100 °C/10 min)
15.50 Juice, TP (100 °C/35 min)
OX325, USA
9.84 Juice, fresh
10.22 Juice, hot break
10.88 Juice, HP (700 Mpa/45 °C/10 min)
10.29 Juice, HP (600 Mpa/100 °C/10 min)
8.49 Juice, TP (100 °C/35 min)
LTLT: Low Temperature, Long Time; HTST: High Temperature, Short Time; HP: High Pressure
processing. Values in italics are obtained by spectrophotometry, otherwise high-performance liquid
chromatography (HPLC)
Table 5. Lycopene content (mg/100 g FW) in tomato and tomato products including the fractions of
trans- and cis-isomers.
Produkt Total
Lycopene
All Trans
Lycopene (% of
Total)
Cis Lycopene (%
of Total) Reference
Conesa tomato paste, Spain,
0.16% fat
Batch 1 (2014)
32.1 29.2 (91.0) 2.9 (9.0)
This study
Conesa tomato paste Spain,
0.16% fat
Batch 2 (2015)
26.6 23.6 (88.7) 3.0 (11.3)
Conesa tomato paste Spain,
0.16% fat
Batch 2 (2015) - Autoclaved
22.8 19.9 (87.3) 2.9 (12.7)
Conesa tomato paste Spain,
0.16% fat
Batch 2 (2015)- Microwaved
22.9 20.1 (87.8) 2.8 (12.2)
Conesa tomato fine chopped,
Spain, 0.04% fat 6.5 5.9 (90.8) 0.6 (9.2)
Heinz ketchup 0.1% fat 11.0 9.4 (85.5) 1.6 (14.5)
Eldorado tomato puree, Italy,
1% fat 32.1 29.4 (91.6) 2.7 (8.4)
Cherry tomatoes 10.14 8.91 (87.9) 1.23 (12.1)
[58]
On-the-vine tomatoes 5.98 5.00 (83.6) 0.98 (16.4)
Roma tomatoes 8.98 7.88 (87.7) 1.10 (12.3)
Tomato paste 57.87 45.94 (79.4) 11.93 (20.6)
Tomato purée 23.46 17.85 (76.1) 5.61 (23.9)
Tomato juice 10.33 8.47 (82.0) 1.86 (18.0)
Tomato ketchup 12.26–14.69 9.40–9.47 (64.4–
76.7)
2.86–5.22
(23.3–35.6)

Foods 2019, 8, 229 13 of 21
4. Utilization of Tomato Side Streams and By-Products
The valorization strategies for tomato waste biomass may be different depending on whether
the primary production is originally intended for the fresh market or for industrial processing. For
the former case, the biomass may mainly consist of surplus tomato due to seasonal overproduction
or fractions perceived as unmarketable for cosmetics reasons, and in the latter of side streams and
byproducts from the processing. Thus, the remainder of this chapter is divided into ‘Fresh tomato’
and ‘Processing’. However, the strategies described are not understood to be necessarily fixed in
these categories, and can be interchanged (i.e., postharvest ripening can also be applied for processing
tomatoes). Nevertheless, chosen strategies will depend on the available technologies and the volumes
of the available biomass, and type of by-product/side stream fraction, which varies considerably in
the countries subject to this case study.
4.1. Fresh Tomato
In Norway and Belgium, as mentioned above, domestically grown tomatoes are at present
predominantly meant for the fresh market. Hence, processing by-products and side streams is not a
big issue. However, mainly due to seasonal overproduction and, to a lesser extent, that a fraction of
the tomatoes is not suitable for fresh market sale (wrong color, maturity level, shape, and injuries),
there have been attempts to develop processing technology for this fraction. The valorization of this
biomass is currently mainly impeded by the high moisture content and corresponding fast decay.
The small volumes, geographical dispersity, and the seasonality make it even more challenging to
process by conventional processing technologies. Alternatively, flexible and mobile processing
technologies may be looked upon to valorize the underutilized tomato biomass. An example is the
proposed novel spiral-filter press technology to refine horticultural by-products including tomato
[86]. This technology alleviates the need of stabilizing the biomass by using expensive drying
technology, and besides, it is flexible and may be used to produce a range of volumes as well as
handle a multitude of different textures [87]. This implies that it may be used for, e.g., apple, berries,
and carrot processing after the high-season tomato processing is over.
Regards the surplus tomato fraction that is predominantly made up of unripe or
underpigmented tomatoes, research has shown that these tomatoes can be turned into marketable
tomatoes very effectively by simple means. In the SusFood1 era-net project ‘SUNNIVA’ [88], a range
of elicitor treatments were tested in postharvest trials to identify efficient elicitor treatments as tools
to influence the content of health-beneficial phytochemicals (HBPC) in tomato raw material and
waste fractions. Products both for industry use and fresh market use were targeted. Results showed
that the waste fractions of tomato could be utilized as valuable sources of HBPC, and also provide
better raw material utilization when subjected to efficient postharvest elicitor treatments. Among the
most promising elicitor treatments for tomatoes were ethylene treatments for pink and waste
fractions (Figure 2). An important point of attention to maximize health benefits of industrial tomato
products as well as tomatoes for fresh consumption is that different types or cultivars of tomatoes
reach their maximum level of the HBPC at different maturity stages.
Figure 2. Example of ethylene treatment. Examples of Calista (a) and Volna (c) varieties that were not
ripe at the time of harvesting and the respective varieties after six days of storage under ethylene
atmosphere (b,d). Adapted from Grzegorzewska et al., 2017 [89], with permission.

Foods 2019, 8, 229 14 of 21
Studies have shown that hormic dosage of ultraviolet radiation (UV-C) can be applied to delay
the senescence of fruit and vegetables, suggesting that photochemical treatment may have the
potential for postharvest preservation of tomato [90]. The effects of UV-C and temperature on
postharvest preservation of tomato are summarized in Tjøstheim, 2011 [91], and long-term controlled
atmosphere and temperature storage in Batu, 2003 [92] and Dominguez et al., 2016 [93]. In short,
temperatures from 12.8 to 15 °C appear to be optimal, but there are large variations between different
cultivars. An example of postharvest lycopene evolution in pink tomatoes at different storage
temperatures is shown in Figure 3.
Figure 3. Lycopene increase (%) in pink harvested processing tomatoes, cv. Calista, during storage in
the dark at 3 different temperatures (12, 20, and 25 °C) and 80% relative humidity. The initial level of
lycopene was about 6.5 mg/100g fresh weight (FW). Rearranged from data previously published in
Sikorska-Zimny et al., 2019 [66], with permission.
A completely different way of valorizing the fraction of tomatoes in the sub-optimal food (SOF)
category, i.e., tomatoes with a color or shape that may be considered undesirable, is to target the
consumers and try to get them more aware of the consequences of food waste. Consumers appear
receptive to discounts on vegetables with imperfections [94]. Since October 2013, under its own brand
“Wunderlinge” (translated as ‘odds’) such fruit and vegetables have been offered in Austria, and
similar actions rapidly spread to neighboring countries [95]. Depending on season, and what is
available, these fruits and vegetables, which, despite their idiosyncratic appearance is flawless in
taste, are offered at a cheaper price. Similar campaigns and the establishments of ‘food-banks’ is
becoming more common throughout Europe, but many actions are still at an experimental stage.
Then there will still be left fractions that are not suitable for recycling into the food chain. Upon
extraction, both tomato fruit waste and vegetative by-products may be utilized as sources of
compounds with pharmaceutical and therapeutic benefits (e.g., phenolic compounds like quercetins,
kaempferol, and apigenin) or cosmetics ingredients (e.g., lactic acids) [96]. Side-flows and waste from
vegetable processing can also be recirculated back to the field in the form of compost and used as
growth substrates. Tomato waste compost may be used to replace partially peat-based substrate used
for vegetable transplants production in nurseries [97]. Tomato side streams may also be used as raw
material for the production of organic fertilizer or soil amendment. However, more research is
needed to document the bio-stimulating effect of tomato waste streams for its potential use as an
input source for such products [88].
4.2. Processing

Foods 2019, 8, 229 15 of 21
During tomato processing, three to seven percent of the raw material is lost as waste [7,98]. The
press cake resulting from tomato juice and sauce production consists of skin and seeds [99]. The seeds
constitute approximately 10% of the fruit and 60% of the total waste, and is a source of protein and
fat [100].
The chemical composition of tomato processing waste fractions was characterized by Al-
Wandawi et al., 1985 [101]. The seed fraction was rich in oleic and palmitic acids, a high protein
content with threonine and lysine as the dominating amino acids, and K, Mg, Na, and Ca as the
dominating elements. Whereas the skin fraction was also rich in proteins with lysine, valine, and
leucine as the predominating essential amino acids, and Ca, K, Na, and Mg as the major elements
[101].
Pure lycopene has traditionally been extracted from tomatoes through processes using chemical
solvents. Innovative supercritical fluid extraction (SFE) methods do not leave behind the chemical
residues associated with other forms of lycopene extraction and were demonstrated by researchers
at the University of Florida to be very efficient and with a greater yield than conventional methods
[102]. Supercritical CO2 extraction using ethanol as a solvent is an efficient method to recover
lycopene and β-carotene from tomato skin by-products [103]. Lenucci et al., 2015 [104] performed
studies on enzymatic treatment of tomato biomass prior to supercritical CO2 extraction of lycopene,
and the results showed that the enzymatic pretreatment could increase the yield of lycopene
extraction by 153% as compared to solvent extraction. Besides enzymatic pretreatment, ultrasound
and microwave-assisted extraction methods, on their own or combined, have been developed for the
extraction of lycopene, resulting in higher extraction yield. Lianfu & Zelong, 2008 [105] compared
combined ultrasound/microwave-assisted extraction (UMEAE) and ultrasonic assisted extraction of
lycopene from tomato paste and achieved a yield of 97.4% and 89.4% for UMAE and UAE,
respectively. UMEAE has thus shown to be highly effective and may also provide rapid extraction
(367 s in the mentioned study [105]). The use of UAE was reviewed by Chemat et al., 2017 [106], who
concluded that the process can produce extracts in concentrate form, free from any residual solvents,
contaminants, or artifacts, and one of the most promising hybrid techniques is UMAE. Supercritical
CO2 extraction has recently been optimized by modelling and resulted in a lycopene yield of 1.32 mg
of extract per kg of raw material obtained by a peel/seed ratio of 70/30 [107], opening for a very
promising future. Similarly, the use of pulsed electric fields (PEF) to improve carotenoid extraction
from tomato was demonstrated [108]. The recent developments in carotenoid extraction methods was
recently reviewed by Saini & Keum, 2018 [109], comparing enzyme-assisted extraction to the methods
mentioned above and Soxhlet extraction.
Lycopene is a high-value compound, costing on the order of 2000 €/kg in its pure form.
Nevertheless, at a 10 mg lycopene per 100 g FW basis, it takes 10,000 kg of tomato fruit to produce 1
kg of pure lycopene even at 100% yield. Hence, in order to be economically sustainable, large volumes
of the tomato raw material are needed. Consequently, this would hardly be feasible in Norway and
Belgium, but may be proposed as a viable valorization strategy in countries like Poland and Turkey.
Some strategies for valorization of tomato side streams and by-products are exemplified in Table 6.
Table 6. Proposed utilization of tomato side streams and by-products from food processing.
Product Active ingredients Fraction Reference
Color pigments,
Antioxidants Lycopene Skin, pomace, whole
fruit [72,102,110]
Tomato seed oil Unsaturated fatty acids (linoleic acid) Seeds [111,112]
Thickening agent Pectin Dried Pomace [113,114]
Comminuted and vegetarian
sausages Dried and bleached tomato pomace Dried Pomace [115]
Tomato seed meals Protein, polyphenols, etc. Seeds, pomace [116]
Nutrient supplements Vitamin B12 Pomace [117]
Cosmetics Phenolic compounds, antioxidants, lactic
acid, etc. Whole plant [96]

Foods 2019, 8, 229 16 of 21
Compost, growth substrates,
fertilizer Phytochemicals Whole plant [97]
5. Conclusions
Tomato side streams, by-products and surplus fractions are underutilized resources estimated
to amount to in excess of 3 million metric tons per year in Europe. The ratios of this biomass that is
consisting of whole fruit versus the processing side-streams are largely unknown. However, in
regions where production is largely dependent on greenhouse production for fresh market sale due
to climatic preconditions (e.g., Norway and Belgium), the fraction is predominantly whole fruit, and
the opposite is the case where tomato processing constitutes a larger industry (e.g., Poland and
Turkey). For the former case, strategies to prolong the postharvest storability of the fruit by, e.g.,
controlled atmosphere, elicitor, light, and temperature to overcome surplus tomatoes due to seasonal
over production for the fresh market may be proposed, combined with novel, sustainable, low-
energy, flexible processing technologies. For the latter case, where volumes of the side fractions make
more sophisticated and targeted technologies economically and environmentally sustainable, several
options for bioeconomical valorization exists, including utilization of by-products in comminuted
hybrid and vegetarian food items, and the extraction of valuable health-beneficial compounds for the
production of functional ingredients, protein-dense meals, and nutrient supplements. Strategies for
utilization of inedible fractions, including the vegetative parts of the tomato plants may be found in
the production of organic fertilizers, biobased materials such as paper, fiberboard, or extracts used in
the cosmetics industries.
The notion that modern consumers are becoming more aware of the health beneficial properties
of tomato and tomato products, and lycopene in particular, should not go unnoticed. Cultivation and
processing practices may be further designed to meet consumer demands and preferences related to
health and nutritional issues, and consequently add value to the tomato supply chain, also through
the fabrication of functional and nutraceutical ingredients from biomass traditionally considered as
waste.
Supplementary Materials: The following are available online at www.mdpi.com/xxx/s1, Table S1: Tomato
production Europe.
Author Contributions: T.L. performed the literature review and wrote the original draft. B.V.D., E.C.E., S.K.,
G.A., M.V., and D.S. provided critical feedback on the draft, edited the text, and helped compile figures and
tables. All authors contributed to the final version of the manuscript, reviewed the final version, and approved
the submission.
Funding: This research was funded by the Research Council of Norway (RCN), grant numbers 238207, 284235,
and 255613. Nofima funded the APC.
Acknowledgments: This study was financed through the two SusFood era-net projects SUNNIVA and InProVe
and RCN project BIOFRESH. T.L. and D.S. acknowledge funding from RCN (project no. 238207 and 284235).
B.V.D. acknowledges funding from the Agency for Innovation by Science and Technology (IWT) – Belgium.
E.C.E. acknowledges funding from the General Directory of Agricultural Research and Policies (GDAR)—
Republic of Turkey. S.K. acknowledges funding from the National Centre for Research and Development
(NCBiR)—Poland. G.A. acknowledges funding from the Daniel and Nina Carasso Foundation (DNCF) and the
Ministry of Agricultural, Food and Forestry Policies (MiPAAF)—Italy. M.V. acknowledges funding from RCN
(project no. 255613). The authors wish to thank Rune Slimestad (NIBIO) and Romain Larbat (INRA, Nancy) for
conducting HPLC analysis of lycopene, and the remaining SUNNIVA consortium for fruitful collaboration.
Conflicts of Interest: The authors declare no conflicts of interest.
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