Modified starch and gum Arabic in freeze-dried orange peel
What it found
In lab tests, adding gum Arabic and modified corn starch to freeze-dried orange juice co-product protected vitamin C, phenols and flavonoids during drying and helped more of them survive simulated digestion.
It did not protect carotenoids.
What they found
Animal and lab studies
Bioaccessibility
After simulated digestion, the samples with biopolymers released more total phenols, flavonoids and carotenoids than the sample without them. Vitamin C was not detected in any digested sample.
Other findings
Phenols and flavonoids
Freeze-drying increased total phenols by about 4% without additives, 20% with the lower level of biopolymers and 35% with the higher level. Hesperidin rose by about 64%, 100% and 140%, and narirutin by about 22%, 35% and 65%, respectively.
Vitamin C
Vitamin C was mostly in its oxidised form. The higher level of modified starch raised vitamin C by about 20% compared with the untreated co-product, and modified starch protected it better than gum Arabic during freeze-drying.
Carotenoids
Carotenoids were not protected. Freeze-drying caused losses of about 39%, and the biopolymers did not prevent this.
Antioxidant capacity
The antioxidant activity of the water-soluble fraction increased in the freeze-dried samples, especially with the higher level of modified starch. The fat-soluble fraction lost 33 to 45% of its activity.
What the authors conclude
“The addition of gum Arabic and modified starch is therefore recommended, as their incorporation seems to prevent, to some extent, the degradation of the studied bioactive compounds and their antioxidant properties during freeze-drying, and improves their release during digestion to be absorbed by the organism.”
Also in their conclusions
- They say the freeze-dried orange juice co-product has high levels of vitamin C, total phenols, flavonoids and carotenoids, with antioxidant properties, and could be useful in food technology.
- They recommend adding gum Arabic and modified starch because they seem to prevent some degradation of these compounds during freeze-drying and improve their release during digestion.
- They suggest that further research with in vivo studies would be interesting to confirm the results obtained in vitro.
How it was done
The orange juice industry generates large amounts of waste peel, and the authors wanted to see if freeze-drying it with these two ingredients could turn it into a useful food ingredient while keeping its beneficial compounds intact.
They mixed orange juice co-product with gum Arabic or modified corn starch at two levels (0.25 and 0.45 grams per gram of dry solids), freeze-dried the mixtures, and measured vitamin C, flavonoids, total phenols, carotenoids and antioxidant capacity before and after a simulated digestion in the lab.
What it can’t tell you
- This was a lab study using a simulated digestion, not real people or animals. It cannot show what actually happens in the human body.
- The digestion model cannot fully copy the complex conditions inside a person, so the amounts absorbed may differ.
Who paid
- Funding
- Funded by Universitat Politècnica de València (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
- Authors work at
- Universitat Politècnica de València, Spain
The paper
- Title
- In Vitro Bioaccessibility of Bioactive Compounds of Freeze-Dried Orange Juice Co-Product Formulated with Gum Arabic and Modified Starch
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- García-Martínez E, Camacho MDM, Martínez-Navarrete N (2023). In Vitro Bioaccessibility of Bioactive Compounds of Freeze-Dried Orange Juice Co-Product Formulated with Gum Arabic and Modified Starch. Molecules (Basel, Switzerland). doi:10.3390/molecules28020810Free full textPubMed 36677869DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error