Post Harvest Management- ICAR JRF/SRF 2024

• Food Sequestrants (Chelating Agents):
• Compounds that bind and complex polyvalent metal ions (such as $\text{Fe}^{2+}, \text{Fe}^{3+}, \text{Cu}^{2+}, \text{Ca}^{2+}$), preventing them from catalyzing lipid oxidation, enzymatic browning, and turbidity.
• Sodium Tartrates and (B) Sodium Citrate: Classic hydroxy-carboxylic acid salts featuring multiple carboxylate and hydroxyl ligand groups that form stable coordination complexes with pro-oxidant metal cations.
• (C) Sodium Nitrate: Antimicrobial and curing agent in processed meats.
• (D) Sodium Isoascorbate (Erythorbate): Direct antioxidant reducing agent.
• Correct Option: Option 1 ((A) and (B) only).

• Statement (I) is True: Low Methoxyl (LM) Pectins (Degree of Esterification $\lt 50\%$) are the industrial standard for formulating dietetic, diabetic, and low-calorie jams and jellies.
• Statement (II) is True: While conventional High Methoxyl (HM) pectins require high soluble solids ($\gt 65\%\text{ sugar}$) and low pH ($2.8 - 3.5$) to form gels through hydrophobic interactions and hydrogen bonding:
• LM pectins form gels via the "egg-box" mechanism, where divalent calcium ions ($\text{Ca}^{2+}$) form ionic crosslinks between unesterified galacturonic acid carboxylate groups.
• This crosslinking occurs independently of sugar concentration, enabling firm gelation with low or zero sugar across a wide pH range ($2.5 - 6.5$).
• Conclusion: Both Statement (I) and Statement (II) are true (Option 1).

Correct option: (1) Both Statement (I) and Statement (II) are true.

• FSSAI Minimum Fruit Content Standards:
• Fruit Preserve (Murabba): Minimum $55\%$ fruit content (m/m) with TSS $\ge 68^{\circ}\text{Brix}$.
• Orange Nectar: Minimum $40\%$ fruit juice content (citrus nectars require higher juice minimums than pulpy nectars).
• Fruit Squash: Minimum $25\%$ fruit juice content with TSS $\ge 40^{\circ}\text{Brix}$ and acidity $1.0\%$.
• Mango Nectar: Minimum $20\%$ fruit puree/juice content with TSS $\ge 15^{\circ}\text{Brix}$.
• Descending Sequence:

• Correct Sequence: (D), (A), (B), (C), matching Option 2.

Correct option: (2) (D), (A), (B), (C).