Freeze drying and spray drying for the retention of the active components, L-theanine and caffeine, and antioxidant activity of tea-based ingredients
Bibliographic record
Abstract
Abstract Preserving food products from oxidation improves their quality and stability. This study compares the effects of storage on L-theanine, caffeine, moisture content and antioxidant activity of spray-dried and freeze-dried white tea infusions. The antioxidant activities of both dried infusions were restored over a 60-day storage. On Day 60, the L-theanine and caffeine levels of the freeze-dried samples were respectively 1.45 ± 0.03 mg mL−1 and 2.23 ± 0.04 mg mL−1 compared with 1.16 ± 0.03 mg mL−1 and 1.97 ± 0.01 mg mL−1 on Day 0. In the spray-dried samples, the L-theanine was 0.32 ± 0.01 mg mL−1 on Day 60 and 0.36 ± 0.02 mg mL−1 on Day 0, while caffeine remained unchanged. Regarding undried/control samples, L-theanine and caffeine declined from respectively 0.29 ± 0.0004 mg mL−1 and 0.33 ± 0.01 mg mL−1 on Day 0 to 0.2 ± 0.001 mg mL−1 and 0.26 ± 0.02 mg mL−1 on Day 60, associated with a decrease in DPPH activity from 75.87% (Day 0) to 15.34% (Day 60). Freeze-drying and spray-drying tea infusions yielded functional products with stable antioxidant activity and moisture. Both drying techniques are reliable for preserving tea preparations.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".