Nanoparticles in Food Lecture Review

Nanoparticles in Food – Study Notes

Overview of the Course

• Instructor: Robert Spiess

• Date: 17.02.2026

• Institution: Bern University of Applied Sciences (Berner Fachhochschule)

• Objectives:

  • Specify approaches to produce nanoparticles.

  • Describe applications of nanoparticles in the food sector and their functions.

  • Evaluate benefits and risks regarding nanoparticles and health.

Agenda

• Introduction

• Selected nanoparticles and potential applications

• Group work

• Safety aspects of nanoparticles in food

Key Concepts

What is Nanotechnology?

• Definition and scope of nanotechnology as relevant to food science.

• Nanotechnology involves manipulating matter on an atomic and molecular scale, typically between 1 and 100 nanometers (nm).

Length Scales of Nanomaterials

• Human Eye: ~ 0.2 mm

• Light Microscopes: ~ 200 nm

• Scanning Electron Microscopy (SEM): 0.5 - 4 nm

• Transmission Electron Microscopy (TEM): 0.5 - 4 nm

  • Maximum resolution: $d \, ext{~} \, rac{ ext{λ}}{2}$ (where $ext{λ}$ is wavelength)

• Atomic Force Microscopy (AFM):

  • X/Y-axis resolution: ~ 1 nm

  • Z-axis resolution: ~ 0.1 nm

Applications of Nanoparticles in Food

Types of Nanoparticles

• Metal Nanoparticles: Used for food preservation, packaging, and delivery systems (e.g., liposomes).

• Organic vs. Inorganic Nanoparticles:

  • Inorganic: Examples include metal oxides like TiO2 (titanium dioxide).

  • Organic: Biopolymers such as nanocapsules used for targeted nutrient delivery.

Functional Roles

• Food Preservation: Extending shelf life through antimicrobial properties.

• Smart Packaging: Interactive packaging that responds to environmental changes.

• Nutrient Delivery: Enhanced bioavailability by encapsulating nutrients.

• Functional Food: Incorporation of active bio-compounds for health benefits.

Safety and Health Concerns

Potential Risks

• Uptake and Accumulation: Concerns about the accumulation of nanoparticles in human bodies.

• Health Outcomes: Risk for cancer, toxicity, and inflammatory diseases related to nanoparticle exposure.

• Concerns on Nanotoxicity: Potential unknown long-term effects on human health.

Regulatory Aspects

• TiO2 Ban:

  • Banned in Switzerland since autumn 2022 and in the EU since January 2022 due to emerging safety concerns.

• EFSA Recommendations:

  • Regular updates and safety evaluations for food additives including nanoparticles.

Visualization Techniques

Electron Microscopy

• SEM and TEM Imaging: Used to visualize nanoparticles down to nm scale with high resolution.

• AFM: Capable of producing height images and analyzing surface topography.

Nanoencapsulation

Benefits of Nanoencapsulation

• Higher Stability: Biological and chemical stability of active compounds.

• Enhanced Solubility: Improved solubility of hydrophobic compounds, achieved through nanoemulsions.

• Controlled Release: Timing of nutrient release can be manipulated, increasing efficacy of bioactive agents.

• Improved Bioavailability: More efficient absorption of nutrients in the body.

  • Notable Example: Encapsulation of key compounds like vitamins in nanoparticles.

Bioavailability Studies

• Studies and data comparing the uptake of nanoparticles relative to particle size (nm).

• Graphical representation of relative bioavailability from different studies, noting significant changes in bioavailability as size decreases.

Mechanisms and Concerns

Pharmacokinetics

• Impacts of nanoparticles on the pharmacokinetics of drugs upon entering systemic circulation.

• Increased bioavailability of certain agents may lead to adverse health effects.

Ethical Considerations

• Discussion on the ethical implications of enhancing bioavailability, especially regarding the tolerable upper intake levels for vitamins such as vitamin E.

• The potential for nanoparticles to facilitate the uptake of non-desirable substances (e.g., pesticides, pollutants).

Iron Fortification Example

Approaches for Enhancing Iron Bioavailability

• Targeted strategies include the encapsulation of iron alongside vitamin A to improve absorption.

• Focus on minimizing absorption inhibitors in dietary formulations.

Group Work

• Form groups of 3-4 for presentations on assigned topics related to nanoparticles:

  1. Interference of triglyceride hydrolysis by nanocellulose.

  2. Exploration of curcumin-encapsulated nanoparticles.

  3. Applications of silver nanoparticles for food packaging.

  4. Use of nisin-loaded pectin nanoparticles for food preservation.

Concluding Remarks

• Nanotechnology is still an emerging field with much to explore.

• Current knowledge on the implications of nanoparticles in food and health requires further research.

• There is a critical need for comprehensive risk assessments tailored to specific nanoparticle types and food matrices.

References

• A range of studies cited throughout the notes (Bolisetty et al., Kamita et al., and EFSA assessments).