Kiwi peel waste enhances manure protein degradation: Statistical optimization using Box-Behnken design and response surface methodology
Bibliographic record
Abstract
Anaerobic digestion (AD) of protein-rich waste is challenged by ammonia accumulation. This study explores the potential of Kiwi peel waste (KPW)-derived proteases (actinidin) to enhance manure protein degradation. It used Box–Behnken response surface design to optimize the protein quantity and ammonia reduction in batch experiments. It studied the individual and interactive effects of the manure degradation parameters (manure dosage, KPW dosage, and time). The optimal manure protein quantity reduction (39 ± 0.54 %) was obtained at manure dosages of 4 g VS L −1 , KPW dosage of 7.5 g VS L −1 , and 48 h. However, the optimum conditions for reducing ammonia by 64 ± 0.65 % are manure dosage of 9 g VS L −1 , KPW dosage of 7.5 g VS L −1 , and 48 h. A highly predictive second-order polynomial model predicted reduction consistent with those observed experimentally ( R 2 = 0.99). Change and decrease in FTIR peak intensity from 3200 to 3400 cm −1 confirmed the disturbance of hydrogen bonds and the breaking of amide or N-H bonds within side chains in the hydrolyzed manure sample. The tests characterizing the hydrolyzed substrate and the statistical model data affirm that employing KPW for manure degradation is a feasible strategy to tackle ammonia buildup. This approach can potentially enhance protein degradation in manure and increase methane yield in AD. Future studies may explore the effects of using different types of manure or other slaughterhouse waste to understand the model’s viability on various protein-rich wastes. The stability of actinidin needs to be investigated under different environmental conditions, such as temperature, pH, nutrients, etc. • Kiwi peel waste (KPW) enhances manure protein hydrolysis, reduces ammonia buildup. • A 2nd-order polynomial model accurately predicted NH 3 reductions ( R 2 = 0.99). • KPW proteases reduce manure protein by 39 ± 0.54 % and NH 3 by 64 ± 0.65 %. • FTIR confirms functional group changes in the Amide region during hydrolysis. • SEM revealed fibrils with cross-striations became smoother after 48 h hydrolysis.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".