ITU

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ITU
Istanbul Technical University

• Food Engineering Department
• Tel [phone] Fax [phone]
  e-mailfood_at_itu.edu.tr http//www.food.itu.edu.t
  rhttp//www.food.itu.edu.tr/en/home.html

Established in 1990
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ITU FLORA Participants

• Prof. Dr. Artemis KARAALI
• Prof. Dr. Dilek BOYACIOGLU
• Assist. Prof. Dr. Beraat ÖZÇELIK
• Assist. Prof. Dr. Gürbüz GÜNES

FLORA
Food chemistry (plant constituents, antioxidants
etc.) Chemical analyses (separations,
instrumental analyses, antioxidative power etc.)
Food Technologies Post-harvest investigations
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ITU Commitments to FLORA

• 1. Work Package 2
• Screening of many plant varieties of fruit and
  vegetables grown in Turkiye or of traditional
  Mediterranean origin, and identification of their
  content of flavonoids and related phenolics
• Determining the antioxidant capacities of
  selected screened samples by in-vitro methods
• Comparing the in vitro antioxidant capacities of
  the model foods engineered during the project.

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ITU Commitments to FLORA

• 2. Work Package 6
• Characterisation of the antioxidant capacities of
  the bioactives identified in these screens.
• Assessment of the effects of processing and
  post-harvest storage of plants on flavonoids and
  related phenolics.
• Evaluation of the effects of food storage and
  processing (freeze drying, irradiation etc) on
  flavonoid and related phenolic composition and
  antioxidant capacity in a range of foods central
  to the Mediterranean diet.

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Summary - Materials

• Dried Fruits
• Dried apricot, SO2 treated dried apricot, raisin,
  dried fig, prune, dried red grape (COMPLETED)
• Rosehip (COMPLETED)
• Dry Chinese date (COMPLETED)
• Raisins (CONTINUED)

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Summary - Materials

• Fruits
• Purple carrot and purple carrot concentrate,
  Shalgam beverage, Pomegranate juice(CONTINUED)
• Pomegranates (Punica granatum) - Pomegranate peel
  and seed extracts and fresh juice (CONTINUED)
• Turkish persimmon (CONTINUED)
• Tomato and tomato products (TAMEK Food Co. in
  Bursa-Turkiye provided raw materials, by-products
  and products) (CONTINUED)

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Summary - Materials

• Herbs and herbal teas
• Nettle (COMPLETED)
• Tea waste (COMPLETED)
• Blackberry leaf, Elderberry flower, Dandelion
  root (CONTINUED)
• Wine
• White and red wines (CONTINUED)

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Summary Experimental Design

• Studies on phenolic content and profile and
  antioxidant activity of selected plants (herbs,
  fruits and vegetables)
• Studies on antioxidant potential in vegetable-oil
  model systems
• Studies by combining both experimental designs

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Study Design 1

• To determine the most efficient extraction
  solvent system for phenolic compounds in
  different food models.
• To determine the amount of total phenolic
  contents (Folin-Ciocalteu method) of plants.
• To investigate antioxidant potentials using the
  following methods
• DPPH radical scavenging activity assay, ABTS
  radical cation decolorisation assay, Superoxide
  anion scavenging activity, Reductive potential,
  AA in linoleic acid emulsion system, Hydroxyl
  radical scavenging and Metal chelating activity
  methods
• Phenolic profile - HPLC method

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Study Design 1

• HPLC Phenolic Profiling Method
• Each phenolic standard was dissolved with
  metOHwater (5050) at certain concentrations and
  injected onto HPLC at the conditions given above.

Other standards that will be identified Tannic
acid, Quercetin, Cinnamic acid, Apigenin,
Kaempferol, Vanillic acid, Rosmarinic acid
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Elderberry flower extract (metOHwater)
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Elderberry flower infusion
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Grape Juice
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Shalgam
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Study Design 2

• To determine the amount of total phenolic
  contents (Folin-Ciocalteu method)
• To evaluate the antioxidative effects of food
  material in olive oil model system
• Addition of dried and ground material added into
  olive oil (25 g/500 g olive oil)
• Storing in glass bottles at two different
  temperatures (25C and 50C) for 8-10 weeks.
• Using control sample and synthetic antioxidant
  with addition of BHT(0.02) and storing under
  same conditions.
• To follow up the induction period using Rancimat
  instrument.
• FFA and Peroxide values were also monitored.

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Study Design 3

• In addition to determination of total phenolic
  contents (Folin-Ciocalteu method) and
  antioxidative effects of food material
• Olive oil model system was used.
• To follow up the induction period using Rancimat
  instrument.

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Studies on Phenolic content and profile and
antioxidant activity of selected plants

• Experimental Design 1

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Herbal Teas (continuing)
Blackberry leaf, elderberry flower and dandelion
root herbs and infusion of those herbs were also
prepared (WP 6)
Accepted for IFT-2006, Orlando
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu, Seda Eruçar (M.Sc.Thesis)
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Herbal Teas
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Herbal Teas
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Tea Industry Wastes (completed)

• Total phenolic content was found to be the
  highest (55.2mg GA/g dry sample) in acetone-water
  extract.
• DPPH radical scavenging activity (SA) for the
  20mg/ml solution of the methanolic extract was
  found to be 38.2.
• The results promise creation of a novel
  value-added product from wastes for the Turkish
  tea industry, an "antioxidant extract"

Accepted for IFT-2006, Orlando
Group Artemis Karaali, Nese Sahin
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Dry Chinese Date (continuing)

• Total phenolic contents were found to be 7.32 mg
  GA/g and 1.48 mg GA/g for methanolic and
  ethanolic extracts, respectively.
• Further antioxidant assays were carried out with
  methanolic extracts.
• For methanolic extracts of dry jujube at 20 mg/ml
  concentration the scavenging activity (SA) was
  16.8 .
• Jujube with its high phenolic content and
  moderate antioxidant potential is a promising
  healthy dry fruit.

Accepted for 2nd International Congress on
Functional Foods and Neutraceuticals, Istanbul
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu
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Persimmon fruit (Diospyros kaki Thumb)
(continuing)

• Total phenolic contents were found to be 3.73 mg
  GA/g sample, 1.73 mg GA/g sample, and 0.73 mg
  GA/g sample, for methanolic, aceton and ethanolic
  extracts respectively.
• For methanolic extracts of fresh persimmon pulp
  at 40 mg/ml concentration scavenging activity
  (SA) of 73.5 was obtained.
• Persimmon with its high phenolic content and
  antioxidant potential is a promising healthy raw
  material for its new applications in food
  industry.

Accepted for IFT2006 in Orlando
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu
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Purple carrot and its concentrate, shalgam drink,
pomegranate juice (continuing)
Group Beraat Özçelik, Tuba Öztan (M.Sc. Thesis)
Accepted for IFT2006 in Orlando
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Purple carrot and its concentrate, shalgam drink,
pomegranate juice
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Turkish wines (continuing)
Group Artemis Karaali, Nese Sahin, Mine
Bayraktar, Çigdem Karakaya (Graduation Project)
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Flavonoid profiles of tomato and the effects of
different processes (continuing)

• Objective
• To determine the flavonoid content of tomatoes
  and their products
• To investigate the effect of several processes
  (e.g. heating, pasteurization, etc.) on the
  flavonoid profile of different products such as
  tomato paste, tomato juice, and tomato puree.
• Samples were collected from each steps of
  processing, starting from the fresh tomato until
  the end product -tomato paste- from a tomato
  paste factory (Tamek Co.), in Turkey (each stage
  at two sampling biological replications).
• Some other processed tomato samples were also
  collected from the market.

Group Dilek Boyacioglu, Esra Çapanoglu (Ph.D.
Thesis)
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Flavonoid profiles of tomato and the effects of
different processes

• Materials
• Tomato fruits
• Breaking step (breaking tomatoes into small
  pieces)
• Finisher pulp (seed and skin parts of the breaked
  tomatoes are separated by filtering, and the pulp
  is processed)
• Finisher seed skin (residue)
• Evaporated out (three effect evaporation of
  finisher pulp (heating up to 80ºC))
• Tomato paste (final product, after
  pasteurization)
• Samples, collected from the market (dried
  tomatoes, tomato juice, tomato paste, diced
  tomato, tomato puree)

Analysis performed in WUR Plant Research
International, Wageningen, Netherlands
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Flavonoid profiles of tomato and the effects of
different processes

• Methods
• Carotenoid analysis (HPLC antioxidant detection
  system)
• Flavonoid analysis (HPLC antioxidant detection
  system)
• Polyphenolic antioxidant analysis (QTOF-MS
  analysis)
• Vitamin C analysis (HPLC method)
• Total Antioxidant analysis (ABTS radical
  scavenging activity method-spectrophotometric)
• Total Antioxidant analysis (DPPH radical
  scavenging activity method-spectrophotometric)
• Total phenolics (Folin-Ciocalteau method)

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Studies on Phenolic content and profile and
antioxidant activity of selected plants

• Experimental Design 2

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Rosehip (Rosae caninae)
Rosehip was found to be an effective natural
antioxidant source during storage of olive oil.
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu
Presented in ISF-2005, Prague
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ROSEHIP (Rosae caninae)
FFA values of BHT involving olive oil had the
lowest value.
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ROSEHIP (Rosae caninae)
Induction period was extended by the addition of
rosehip.

• The total phenolic content of the rosehip was
  found to be 33.75 mg GAE/g sample by using
  Folin-Ciocalteu method.
• Scavenging activities of the rosehip at 2,083
  mg/ml concentration on DPPH radical was 52.29.

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NETTLE (Urticae herba)
The peroxide values fluctuated from week to week
for nettle-involving olive oil sample stored at
25oC.
Presented in ISF-2005, Prague
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu
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Nettle (Urticae herba)
FFA values were in increasing trend and highest
values were obtained for the nettle-containing
samples for all weeks at both temperatures.
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Nettle (Urticae herba)
The protection factor of nettle was found to be
as high as BHT at 25C, however its efficiency
decreases as the temperature increases.

• The total phenolic content of the nettle 22.63
  mg GAE/g sample
• Scavenging activities of the nettle at 2,083
  mg/ml concentration on DPPH radical was 52.57,
  which shows that nettle has an antioxidative
  power.

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Dried fruits
Among those dried fruits, prune had the highest
amount of total phenolic compound and antioxidant
activity.
Presented in IFT 2005 New Orleans
Group Dilek Boyacioglu, Dilara Nilüfer, Esra
Çapanoglu, Esra Çakir Hicran Koç (Graduation
Project)
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Dried fruits
The scavenging activities of dried fruits were
found to be significantly different (plt0.05).
Prunes showed the highest percentage of
inhibition (89.90) which was not significantly
different from that of BHA (plt0.05).
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Dried fruits
Statistically significant relationship found
between total phenolics and DPPH radical
scavenging activity (R20.7215, plt0.05).
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Dried fruits
Dried apricot showed the highest protection,
there was no statistically significantly
different between samples (pgt0.05). Therefore, it
is proposed that prune exerts an antioxidant
activity as high as the synthetic antioxidant,
BHA.
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RESEARCH TOPICS PLANNING

• Gürbüz GÜNES
• To study the effect of storage and minimal
  processing on flavonoid composition and
  antioxidant activity of fruits and vegetables.
• Mulberry, pomegranate, strawberry, raspberry,
  Amasya apples and red cabbage
• Cold air storage, controlled atmosphere storage,
  modified atmosphere packaging, 1-MCP
  (1-methylcyclopropene) treatments, and minimal
  processing

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RESEARCH TOPICS PLANNING

• A variety of fruit juices Pomegranate, grape,
  apple, and orange juice
• Traditional thermal processing parameters and
  also high-pressure CO2 treatments

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RESEARCH TOPICS PLANNING

• Dilek BOYACIOGLU
• Evaluating the phenolic contents/profiles and
  antioxidant activities of cocoa and chocolate
• To investigate the effects of processing steps
  during chocolate processing on the phenolic
  contents and antioxidant activities of cocoa as
  the raw material of chocolate.
• Materials
• natural cocoa powder, alkalized cocoa powder,
  cocoa mass, dark and milk chocolates.

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RESEARCH TOPICS PLANNING

• Dilek BOYACIOGLU
• Preliminary data
• Total phenolics
• Natural cocoa 5,8 mg GA/g defatted sample
• Alkalized cocoa 0,04 mg GA/g defatted sample
• DPPH Radical Scavenging activity
• Natural cocoa 22,36 (5mg defatted sample/ml)
• Alkalized cocoa 6,25 (5mg defatted sample/ml)

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RESEARCH TOPICS PLANNING

• Artemis KARAALI
• Materials (WP6 effects of processing)
• Grapes, raisins, wines (white, red, pink), olives
  (green, black) and olive oils
• Capillary electrophoresis as alternative method
  to HPLC for characterising polyphenols in
  previous studies (WP2 further analytical
  characterisation methods)