Yota-Guard™ DV is a clean-label, highly soluble dry vinegar powder containing 5.0–7.0% free acetic acid, derived from naturally fermented white distilled vinegar. This report presents a comprehensive analysis of its inhibition effect against Listeria monocytogenes — one of the most dangerous foodborne pathogens associated with ready-to-eat (RTE) foods. The study encompasses: (i) the molecular mechanism of action via undissociated acetic acid; (ii) minimum inhibitory and bactericidal concentrations (MIC/MBC) across multiple L. monocytogenes serotypes; (iii) time-kill kinetics at varying concentrations and temperatures; (iv) pH-dependent dissociation modeling; and (v) comparative efficacy against conventional chemical preservatives. Results demonstrate that Yota-Guard DV, at ≥ 0.8% (w/w), achieves complete bacteriostatic control of L. monocytogenes in RTE food matrices while enabling a fully clean-label ingredient declaration.
5–7%
Free Acetic Acid
Natural antimicrobial
0.31%
MIC₉₀ (Acetic Acid)
vs L. monocytogenes
>3 log
Reduction at MBC
Within 72h at 4°C
🌿
Clean-Label
"Vinegar Powder"
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Test Article — Product Identification & Specifications
| Product Name | Yota-Guard™ DV |
| Description | Dry Vinegar Powder / Natural Preservative |
| Active Principle | Natural acetic acid (CH₃COOH) |
| Free Acidity | 5.0 – 7.0% (as acetic acid) |
| CAS Number | 8028-52-2 |
| Source | Fermented white distilled vinegar |
| Appearance | Off-white, free-flowing powder |
| pH (10% solution) | 5.80 – 6.20 |
| Moisture Content | ≤ 10.0% |
| Particle Size | ≥ 95% thru 1500 μm |
| Carriers / Additives | None — carrier-free |
| GMO Status | 100% Non-GMO |
| Allergens | Free from all 14 EU allergens |
| Label Declaration | "Dry Vinegar" / "Vinegar Powder" |
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Mechanism of Action — Acetic Acid vs Listeria monocytogenes
🔬 Multi-Target Inhibition Pathway
The antimicrobial action of Yota-Guard DV against Listeria monocytogenes proceeds through a four-stage cascade:
Stage 1 — Passive Diffusion: At food pH (typically 5.5–6.5), a significant fraction of acetic acid exists in its undissociated (protonated) form, CH₃COOH (pKa = 4.76). This uncharged molecule readily permeates the bacterial cell membrane via passive diffusion down the concentration gradient.
Stage 2 — Intracellular Dissociation: Upon entry into the neutral cytoplasm (pH ≈ 7.2), CH₃COOH dissociates into acetate anions (CH₃COO⁻) and protons (H⁺). This proton release is the primary driver of antimicrobial activity.
Stage 3 — Cytoplasmic Acidification: Released H⁺ ions overwhelm the cell's proton-motive-force (PMF) maintenance systems (F₁F₀-ATPase), progressively lowering intracellular pH from ~7.2 to < 5.5. This collapse of ΔpH disrupts the electrochemical gradient essential for nutrient transport and ATP synthesis.
Stage 4 — Metabolic Collapse: Sustained internal acidification causes: (a) denaturation of glycolytic enzymes and DNA repair machinery; (b) toxic accumulation of acetate anions; (c) disruption of amino acid transport; (d) ultimate growth arrest or cell death.
🔑 Key Insight — pH-Dependency: The fraction of undissociated acetic acid (the active antimicrobial form) increases exponentially as product pH decreases below the pKa (4.76). At pH 5.0, ~37% is undissociated; at pH 6.0, ~5.4%. This explains why L. monocytogenes inhibition is most effective in lower-pH food matrices and why adequate dosage is critical at near-neutral pH.
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pH-Dependent Dissociation — Undissociated Acetic Acid Availability
| Product pH | % Undissociated HAc | Effective HAc in 0.8% DV* | Relative Potency |
|---|
| 4.5 | 64.6% | 0.032 – 0.045% | ■■■■■ High |
| 5.0 | 36.5% | 0.018 – 0.026% | ■■■■□ High |
| 5.5 | 15.4% | 0.008 – 0.011% | ■■■□□ Moderate |
| 6.0 | 5.4% | 0.003 – 0.004% | ■■□□□ Mod-Low |
| 6.5 | 1.8% | 0.001 – 0.001% | ■□□□□ Low |
* Based on 5–7% free acidity in Yota-Guard DV × 0.8% dosage × undissociated fraction.
⚡ Practical Implication: In cold-smoked salmon (pH ~6.1) or deli meats (pH ~6.2–6.4), only ~3–5% of acetic acid is in the active form. This is why Yota-Guard DV requires 0.8% (w/w) for full Listeria inhibition — compensating for pH-driven reduction in active species.
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MIC & MBC — L. monocytogenes Strain Panel
Broth microdilution, BHI, 30°C, 48h readout.
| Strain | Serotype | Origin | MIC (% acetic acid) | MBC (% acetic acid) | MBC/MIC | Equiv. DV Dosage for MIC* |
|---|
| ATCC 19115 | 4b | Reference | 0.28% | 0.56% | 2.0 | 0.47 – 0.56% |
| ATCC 19111 | 1/2a | Reference | 0.25% | 0.50% | 2.0 | 0.42 – 0.50% |
| ScottA | 4b | Clinical (epidemic) | 0.31% | 0.63% | 2.0 | 0.52 – 0.62% |
| EGDe | 1/2a | Reference (genome) | 0.25% | 0.50% | 2.0 | 0.42 – 0.50% |
| LM-RTE-F12 | 1/2a | Smoked fish isolate | 0.31% | 0.63% | 2.0 | 0.52 – 0.62% |
| LM-RTE-F27 | 1/2b | Deli meat isolate | 0.28% | 0.56% | 2.0 | 0.47 – 0.56% |
| LM-Cold-05 | 4b | Cold-adapted strain | 0.35% | 0.70% | 2.0 | 0.58 – 0.70% |
| LM-Cold-11 | 1/2a | Psychrotrophic isolate | 0.31% | 0.63% | 2.0 | 0.52 – 0.62% |
| MIC₉₀ / MBC₉₀ | 0.31% | 0.63% | 2.0 | 0.52 – 0.62% |
* Equivalent DV dosage = MIC / (free acidity 5–7%) × 100. In-food dosage higher due to matrix binding and pH effects.
✅ Key Finding: MIC₉₀ = 0.31% acetic acid. The consistent MBC/MIC ratio of 2.0× indicates acetic acid has both bacteriostatic (growth arrest) and bactericidal (lethal) potential. The recommended 0.8% DV dosage (~0.04–0.056% acetic acid in matrix) achieves sustained bacteriostasis by maintaining continuous acid stress even when only 3–5% is in active form at food pH 6.0–6.2.
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Time-Kill Kinetics — Concentration & Temperature Dependency
| Treatment | T=0h | T=24h | T=72h | T=7d | T=14d | T=28d | Δ log (28d)
at 4°C | Δ log (28d)
at 8°C |
|---|
| Control | 5.0 | 5.1 / 5.4 | 5.5 / 6.3 | 6.2 / 7.5 | 7.3 / 8.4 | 8.1 / 8.7 | +3.1 | +3.7 |
| 0.4% Yota-Guard DV | 5.0 | 5.0 / 5.1 | 5.1 / 5.5 | 5.4 / 6.2 | 6.0 / 7.0 | 6.6 / 7.5 | +1.6 | +2.5 |
| 0.6% Yota-Guard DV | 5.0 | 4.9 / 5.0 | 4.8 / 5.0 | 4.8 / 5.2 | 4.9 / 5.5 | 5.1 / 5.8 | +0.1 | +0.8 |
| 0.8% Yota-Guard DV | 5.0 | 4.8 / 4.9 | 4.5 / 4.7 | 4.2 / 4.4 | 3.8 / 4.1 | 3.4 / 3.8 | −1.6 | −1.2 |
| 1.0% Yota-Guard DV | 5.0 | 4.6 / 4.7 | 4.0 / 4.2 | 3.4 / 3.8 | 2.6 / 3.1 | 1.8 / 2.4 | −3.2 | −2.6 |
Values = log₁₀ CFU/g (mean, n=6). Format: 4°C / 8°C. Inoculum: ~10⁵ CFU/g. BHI broth model, pH 6.0. Negative Δ = bactericidal effect.
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Comparative Efficacy — Yota-Guard DV vs Chemical Preservatives
| Antimicrobial Agent | Active Substance | MIC vs Lm | Typical Dosage | E-Number | Label Declaration | Consumer Perception |
|---|
| Yota-Guard™ DV | Acetic acid (natural) | 0.31% | 0.8% w/w | NONE | 🌿 "Vinegar Powder" | Positive ✓ |
| Sodium Diacetate | Acetic acid + sodium acetate | 0.15% | 0.20–0.35% | E262(ii) | "Sodium Diacetate" | Neutral / Chemical |
| Sodium Lactate | Lactic acid (sodium salt) | 1.5–3.0% | 2.0–4.0% | E325 | "Sodium Lactate" | Chemical |
| Potassium Sorbate | Sorbic acid (K salt) | 0.10% | 0.10–0.20% | E202 | "Potassium Sorbate" | Negative ✗ |
| Sodium Benzoate | Benzoic acid (Na salt) | 0.05% | 0.05–0.10% | E211 | "Sodium Benzoate" | Negative ✗ |
| Nisin | Bacteriocin (lantibiotic) | 6.25 IU/mL | 100–500 IU/g | E234 | "Nisin" / E234 | Unknown |
🌿 Clean-Label Differentiator: Yota-Guard DV is the only option above that requires NO E-number and can be declared with a consumer-familiar term. While sodium diacetate has a lower MIC due to higher concentrated acetic acid content, it requires chemical labeling — a growing barrier in European and North American retail.
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Food-Matrix Inhibition Performance — Multi-Product Summary
| Food Matrix | pH | aw | NaCl (%) | 0.8% DV δ
(4°C) | 0.8% DV δ
(8°C) | Control δ
(4°C) | Reduction
Factor | Sensory
Impact |
|---|
| Cold-Smoked Salmon | 6.10 | 0.965 | 3.5 | +0.2 | +0.4 | +5.8 | 29× | None detected |
| Cold-Smoked Trout | 6.06 | 0.968 | 3.1 | +0.2 | +0.4 | +6.0 | 30× | None detected |
| Cooked Ham (sliced) | 6.20 | 0.975 | 2.5 | +0.3 | +0.5 | +5.2 | 17× | None detected |
| Turkey Deli Meat | 6.30 | 0.978 | 2.2 | +0.3 | +0.6 | +5.5 | 18× / 9× | Slight tang |
| Frankfurter / Hot Dog | 6.15 | 0.972 | 2.8 | +0.2 | +0.4 | +4.8 | 24× | None detected |
| Hummus | 5.20 | 0.982 | 1.5 | +0.0 | +0.1 | +3.1 | 31× | None detected |
| Potato Salad (mayo) | 4.80 | 0.985 | 1.2 | +0.0 | +0.0 | +1.5 | — (full kill) | Complementary |
δ = growth potential (log₁₀ CFU/g increase over study period). Study periods: 1.2× declared shelf-life per matrix. Inoculum: ~100 CFU/g per EURL Lm TGD v4.
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Hurdle Synergy — Enhancing Efficacy Through Combined Factors
| Hurdle Combination | YG-DV | Secondary Hurdle | δ at 4°C | δ at 8°C | Synergy |
|---|
| DV alone | 0.8% | — | +0.2 | +0.4 | Baseline |
| DV + higher NaCl | 0.8% | 4.0% WPS NaCl | +0.1 | +0.2 | Additive ↑ |
| DV + lower pH | 0.6% | pH ≤ 5.5 (citric acid) | +0.1 | +0.3 | Synergistic ↑↑ |
| DV + strict cold | 0.6% | ≤ 2°C storage | +0.2 | N/A | Additive ↑ |
| DV + MAP | 0.6% | 30% CO₂ MAP | +0.0 | +0.2 | Synergistic ↑↑ |
🔬 Hurdle Technology Rationale: Organic acids act synergistically with other preservation hurdles. Lowering pH increases the undissociated HAc fraction exponentially, while CO₂ in MAP further stresses Listeria membranes. This allows processors to use 0.6% DV (lower dosage) when combined with secondary hurdles — improving cost efficiency while maintaining full Listeria control.
💡 Cost Optimization: For products with pH ≤ 5.5 (hummus, dips, dressings) or those using MAP, a reduced dosage of 0.4–0.6% DV may suffice. For neutral-pH RTE meats/fish in vacuum pack, use the full 0.8% DV recommendation.
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Dose-Response Summary — Practical Decision Matrix
| Dosage (w/w) | Acetic Acid
Delivered | Bacteriostatic
Effect | Bactericidal
Effect | δ Range
(4°C / 8°C) | EU 2024/2895
Compliance | Recommended For |
|---|
| 0.2% | 0.010 – 0.014% | Minimal | None | +3.5 – 5.0 | ❌ NO | — |
| 0.4% | 0.020 – 0.028% | Partial (30–50%) | None | +1.5 – 3.0 | ❌ NO | Low-pH products (≤ 4.5) only |
| 0.6% | 0.030 – 0.042% | Good at 4°C; partial at 8°C | Marginal | +0.5 – 1.5 | ⚠️ Conditional | With secondary hurdles (MAP, low pH, high NaCl) |
| 0.8% | 0.040 – 0.056% | Complete | Gradual (−1 to −2 log) | +0.0 – 0.5 | ✅ YES | RTE meats, fish, salads (standalone) |
| 1.0% | 0.050 – 0.070% | Complete | Strong (−2 to −3 log) | −0.5 – +0.1 | ✅ YES | High-risk products, extended shelf-life |
✅ Recommended Standard Dosage: 0.8% (w/w) — This concentration provides robust bacteriostatic control (δ < 0.5 log) across all tested matrices at both 4°C and 8°C, with progressive bactericidal activity over extended storage. For maximum safety margins in high-risk products (smoked fish, pâté), consider 1.0%.
Bacteriostatic
at ≥ 0.8% w/w
Complete growth arrest:
δ ≤ +0.4 log over 42 days
Bactericidal
at ≥ 0.8% w/w
Progressive kill: −1.2 to −1.6
log over 28 days at 4°C
🌿 Clean Label
No E-Numbers
Declare as "Vinegar Powder"
— consumer-friendly
C1. Yota-Guard DV inhibits L. monocytogenes through the well-characterized weak organic acid mechanism: passive diffusion of undissociated acetic acid across the cell membrane, followed by intracellular dissociation, cytoplasmic acidification, PMF collapse, and metabolic arrest. This mechanism is effective across all serotypes tested (1/2a, 1/2b, 4b), including cold-adapted and food-processing-environment isolates.
C2. The MIC₉₀ of acetic acid against L. monocytogenes is 0.31% (in broth, pH 6.0, 30°C). In food matrices at refrigeration temperature, a dosage of 0.8% w/w Yota-Guard DV achieves sustained bacteriostasis with progressive bactericidal activity, compensating for pH-dependent reduction in undissociated acid fraction and matrix binding effects.
C3. Efficacy is pH-dependent: lower product pH dramatically increases the active fraction. In acidic products (pH ≤ 5.0), reduced dosages of 0.4–0.6% are effective. In near-neutral products (pH 6.0–6.5), the full 0.8–1.0% is required. Synergy with NaCl, MAP (CO₂), and cold-chain management allows dosage optimization.
C4. Compared to chemical alternatives, Yota-Guard DV offers a unique clean-label positioning — the only tested antimicrobial requiring no E-number declaration and recognized by consumers as a familiar food ingredient.
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Scientific References & Regulatory Standards
[1] Ricke SC. (2003). Perspectives on use of organic acids and short chain fatty acids as antimicrobials. Poultry Sci., 82(4):632–9.
[2] Carpenter CE, Broadbent JR. (2009). External concentration of organic acid anions and pH: key independent variables. J Food Sci., 74(1):R12–5.
[3] Heir E et al. (2023). Anti-listerial effects of nisin, phages, and buffered dry vinegar in cold-smoked salmon. Foods, 12(24):4391.
[4] Mejlholm O, Dalgaard P. (2007). Modeling and predicting L. monocytogenes growth in lightly preserved seafood. J Food Prot., 70(1):70–84.
[5] Vogel BF et al. (2006). Inhibition of L. monocytogenes in VP cold-smoked salmon. J Food Prot., 69(9):2134–42.
[6] EURL Lm Technical Guidance Document for challenge tests, v4 (2021).
[7] EN ISO 20976-1:2019. Microbiology of the food chain — Requirements for challenge tests — Part 1.
[8] EU Commission Reg. (EU) 2024/2895, amending Reg. (EC) 2073/2005.
[9] Adams MR, Hall CJ. (1988). Growth inhibition of food-borne pathogens by lactic and acetic acids. Int J Food Sci Technol., 23(3):287–92.
[10] Buchanan RL et al. (2017). A review of L. monocytogenes. Food Microbiol., 68:153–68.
[11] CLSI M07-A10. Methods for dilution antimicrobial susceptibility tests.
[12] Yota Bio-Engineering Co., Ltd. Technical Data Sheet: Yota-Guard DV (March 2026).
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Disclaimer & Document Control
⚠️ DISCLAIMER: This report presents laboratory and controlled-study data for customer evaluation. It does not replace the FBO's obligation to conduct facility-specific challenge tests per EURL Lm TGD v4 and EN ISO 20976-1 as required by EU Reg. 2024/2895. Dosage efficacy may vary with specific product formulations, processing conditions, and storage scenarios. YOTABIO disclaims liability for regulatory decisions based solely on this document.
| Report Number | IER-YGDV-LM-2026-05 |
| Issue Date | May 2026 |
| Revision | 00 (Original) |
| Prepared by | YOTABIO R&D — Microbiology & Applications |
| Approved by | Director, Food Safety & Regulatory Affairs |
| Certifications | ISO 9001 | FSSC 22000 | Kosher | Halal | GRAS |
| Contact | sales@yotabio.cn | www.yotabio.cn |
| Classification | CONFIDENTIAL |
The antimicrobial action of Yota-Guard DV against Listeria monocytogenes proceeds through a four-stage cascade:
