Fining agents in fruit juice and beverage processing are clarifying aids (typically positively charged proteins like gelatin, egg white albumen, casein, or isinglass, and mineral adsorbents like bentonite) that bind negatively charged polyphenols and suspended hazes. Sorbitol is a sugar alcohol used as a humectant and non-cariogenic bulk sweetener, not a fining agent.

Option analysis:

• Gelatin: Positively charged protein fining agent that precipitates tannins and suspended hazes.
• Albumen: Egg white protein widely used for clarifying juices and wines.
• Sorbitol: Correct, it is a polyol sweetener and moisture-retention agent, not a fining agent.
• Casein: Milk protein fining agent used to remove excess tannins and brown pigments.

When starch granules are heated in excess water, hydrogen bonds in the crystalline regions disrupt, causing water uptake, rapid swelling, and irreversible loss of the characteristic 'Maltese cross' polarization pattern (loss of optical birefringence). The temperature range where this transition occurs is defined as the gelatinization temperature (typically $60 - 75^\circ\text{C}$ for cereal starches).

Option analysis:

• Retrogradation temperature: Re-association and crystallization of amylose chains upon cooling.
• Gelatinization temperature: Correct, temperature at which crystalline order collapses and granules swell with loss of birefringence.
• Cooking temperature: General non-scientific operational term.
• Boiling temperature: Temperature at which liquid vapor pressure equals atmospheric pressure ($100^\circ\text{C}$).

Propionic acid ($CH_3-CH_2-COOH$) and its calcium and sodium propionate salts are widely used antimycotic preservatives in bakery products. Its antimicrobial toxicity to molds and rope-forming bacteria (such as Bacillus subtilis) is attributed to the inability of susceptible microorganisms to metabolize the 3-carbon carboxylate skeleton, which competitively inhibits cellular dehydrogenase enzymes and pyruvate metabolism.

Option analysis:

• Sorbic acid: A 6-carbon unsaturated fatty acid ($C_6H_8O_2$) that inhibits sulfhydryl enzymes.
• Benzoic acid: A 7-carbon aromatic monocarboxylic acid ($C_7H_6O_2$).
• Acetic acid: A 2-carbon aliphatic acid ($CH_3COOH$).
• Propionic acid: Correct, the classic 3-carbon aliphatic organic acid preservative.