Given below are two statements: Statement (I) : Lactose in... | Agrigyan

Analytical reagent chemistry for milk preservatives:

• Boric acid / Borax is detected using acidified Turmeric Paper, which turns characteristic reddish-brown (forming rosocyanin) and turns greenish-black with ammonia $\to$ (IV).
• Formaldehyde is detected by Hehner's test using concentrated $H_2SO_4$ containing trace Ferric chloride ($FeCl_3$), producing a distinct violet/purple ring at the junction $\to$ (III).
• Hydrogen peroxide is detected using a $2\%$ aqueous solution of Paraphenylenediamine, which oxidizes to produce an intense deep blue colour $\to$ (II).
• Hypochlorite / Chloramines are detected using Stannous chloride solution (or KI-starch paper), producing a yellow/brown colour $\to$ (I).

Chromatographic detection of vegetable oils in milk fat:

• Animal fats (ghee) contain cholesterol as virtually their sole sterol ($\gt 99\%$), whereas vegetable oils contain distinctive phytosterols, primarily $\beta$-sitosterol, stigmasterol, and campesterol. The RP-HPLC (Reversed-Phase High-Performance Liquid Chromatography) method adopted by FSSAI directly separates and quantifies unsaponifiable sterols, using the detection of $\beta$-sitosterol as an unambiguous chemical marker for vegetable oil adulteration in ghee.
• Baudouin test detects sesame oil using furfural-HCl.
• Hehner test detects formaldehyde.
• Holde test detects mineral oils.

Physical chemistry of sandiness defect in concentrated milks:

• Assertion (A) is false: The defect 'sandiness' is caused exclusively by the crystallization of LACTOSE (specifically large $\alpha$-lactose monohydrate crystals), NEVER by sucrose. Sucrose has a high solubility (~$67\%$) and remains completely in true solution (sucrose acts as a preservative by increasing osmotic pressure).
• Reason (R) is true: $\alpha$-lactose monohydrate crystals are notoriously hard, slow to dissolve, and when they grow beyond $15\text{--}30\text{ }\mu\text{m}$ in length due to improper cooling/seeding, the human tongue detects them as gritty sand-like grains, giving rise to the name 'sandiness'.