Technical Assistant Grade II (SR for ST only) — Kerala PSC PYQ Practice with Answers

Correct answer (Option B):\nCaramelan is a complex mixture formed during the controlled heat treatment of carbohydrates, specifically through the caramelization process. Heating levolusan at 135°C for 55 minutes leads to the dehydration and dimerization processes that yield caramelan, a key pigment component responsible for the characteristic light brown color and flavors.\n\nWhy others are wrong:\nOption A is incorrect because heating isosachrosan at 155°C for 30 minutes promotes higher molecular weight structures like caramelen rather than caramelan. Options C and D involve simple sugars under conditions that do not primarily target the specific dehydration pathways characteristic of isolated levolusan conversion to caramelan.\n\nRemember:\nCaramelization involves three distinct structural stages of browning polymers: caramelan, caramelen, and caramelyn, each progressing with increasing temperature and heating duration.

Correct answer (Option A):\nNaringinase is an enzyme complex capable of hydrolyzing naringin, which is the bitter compound predominantly found in citrus fruits like grapefruits and oranges. By breaking down naringin into prunin and eventually into non-bitter naringenin, this enzyme is widely deployed in food processing to debitter fruit juices.\n\nWhy others are wrong:\nOption B (Pullulanase) is a debranching enzyme primarily used to hydrolyze starch components. Option C (Pectinase) breaks down pectin to clarify juices and improve yield. Option D (Cellulase) degrades cellulose structural walls to extract more juice, but none of these process bitter glycosides.\n\nRemember:\nBitterness in citrus fruits is majorly attributed to limonoids and flavanone glycosides like naringin. Enzymatic treatment using naringinase is highly specific and retains nutritional quality better than chemical methods.

Correct answer (Option B):\nAsparaginase is used to reduce acrylamide formation in fried or baked starchy foods. Acrylamide forms via the Maillard reaction between reducing sugars and the amino acid asparagine at high temperatures. Treating raw food material with asparaginase converts asparagine into aspartic acid, effectively removing the precursor required for acrylamide synthesis.\n\nWhy others are wrong:\nOption A is a distractor and not a standard commercial food enzyme. Option C (Lipase) breaks down fats into glycerol and fatty acids. Option D (Glucoisomerase) converts glucose to fructose and does not participate in amino acid mitigation pathways.\n\nRemember:\nAcrylamide is recognized as a potential carcinogen. Utilizing immobilized asparaginase prevents the accumulation of toxic compounds during high-heat processes like frying potato chips or baking biscuits without altering food flavor.

Correct answer (Option C):\nRefractive Index (RI) detectors are universally used for analyzing monosaccharides in HPLC. Monosaccharides lack specific chromophores required for strong ultraviolet absorbance, making standard UV-vis detection poorly responsive. RI detectors track variations in the solute concentration by measuring bending light properties, proving highly effective for carbohydrates.\n\nWhy others are wrong:\nOption A (UV-vis) is inefficient because native sugars do not possess functional groups that absorb light well in the ultraviolet spectrum. Options B (TCD) and D (PID) are gaseous phase detectors widely specific to Gas Chromatography (GC) systems, not standard liquid chromatography columns.\n\nRemember:\nBecause RI detectors are sensitive to shifts in temperature and mobile phase compositions, modern monosaccharide profiles also utilize high-performance anion-exchange chromatography paired with pulsed amperometric detection (HPAEC-PAD).

Correct answer (Option A):\nNon-enzymic browning, particularly the Maillard reaction, primarily initiates via a nucleophilic attack of an amino acid's free amino group onto the reactive carbonyl group of a reducing sugar. Basic amino acids containing highly reactive nucleophilic side chains—specifically Lysine (with its ε-amino group), Arginine, and Ornithine—exhibit the highest structural reactivity.\n\nWhy others are wrong:\nOptions B and C contain acidic amino acids like Aspartic acid and Glutamic acid, which possess carboxyl side groups that suppress or do not accelerate nucleophilic attacks. Option D contains hydrophobic branch-chained amino acids which demonstrate significantly lower structural reactivity rates in basic sugar systems.\n\nRemember:\nLysine is typically the most vulnerable amino acid during thermal food handling, which frequently decreases the available nutritional protein value of cooked foods.