# How long can you store vitamins? Stability of tocopherols and tocotrienol during different storage conditions in broccoli and blueberries

## TL;DR

This study examines how different storage conditions affect vitamin levels in broccoli and blueberries, finding that blueberries retain α-tocopherol better than broccoli.

## Contribution

The study provides new insights into the stability of tocopherols and tocotrienol in broccoli and blueberries under various storage conditions.

## Key findings

- Blueberries stored at −20 °C showed consistent α-tocopherol levels over 28 days.
- Broccoli stored at −20 °C showed decreasing α-tocopherol levels over 28 days.
- Freeze-dried broccoli had higher α-tocopherol levels compared to fresh broccoli.

## Abstract

Differences between the stability of α-, β-, γ-, and δ-tocopherol as well α-tocotrienol stored at −20 °C and −80 °C were studied in broccoli and blueberry samples. Before storage up to 28 days, they underwent different initializing processes such as freezing quickly with liquid nitrogen and freeze-drying, followed by homogenization. While α-tocopherol levels in blueberries did not significantly differ, levels in broccoli were substantially higher after homogenization of freeze-dried samples compared to fresh broccoli samples. This might be caused by higher extractability of α-tocopherol from the changed cell structure. Storage of fresh broccoli samples at −20 °C led to decreasing α-tocopherol levels. Nevertheless, the deviation between freeze-dried samples to the initial fresh samples and fresh samples frozen with liquid nitrogen stored at −20 °C for 7 days were in the same order of magnitude. In conclusion, storage up to 7 days for vitamin relevant samples before analysis seemed to be justifiable.

•Blueberries: α-tocopherol levels consistent over 28 days at −20 °C.•Broccoli: α-tocopherol levels decreased over 28 days at −20 °C.•Higher α-tocopherol levels in freeze-dried compared to fresh broccoli.

Blueberries: α-tocopherol levels consistent over 28 days at −20 °C.

Broccoli: α-tocopherol levels decreased over 28 days at −20 °C.

Higher α-tocopherol levels in freeze-dried compared to fresh broccoli.