List of top Questions asked in GATE Engineering Sciences

Match the following food products in Column I with their corresponding processes in Column II.
Which of the following is/are inhibitor(s) of enzymatic browning in peeled potatoes?
Match the following enzymes in Column I with their applications in Column II.
The \(F_{121}\) value of a known microorganism with \(Z\) value of \(11~^\circ\mathrm{C}\) is \(2.4\) min for \(99.9999%\) inactivation. For a \(12D\) inactivation of the said microorganism at \(143~^\circ\mathrm{C}\), the \(F\) value (in min) is \underline{\hspace{2cm}. (rounded off to 3 decimal places)}
A fruit juice is concentrated using an ultrafiltration membrane. A feed stream at \(10~\mathrm{kg/min}\) with \(6%\) total solids (by weight) is increased to \(20%\) total solids (by weight). The membrane tube has \(10~\mathrm{cm}\) inside diameter and the pressure difference across the membrane is \(2000~\mathrm{kPa}\). If the permeability constant of the membrane is \(5 \times 10^{-6}\ \mathrm{kg\ water/(m^2\ kPa\ s)\), the length of membrane tube (in m) is \underline{\hspace{2cm}}. (rounded off to 2 decimal places)}
In a typical grinding operation, \(80%\) of the feed material passes through a sieve opening of \(4.75~\mathrm{mm}\); whereas, \(80%\) of the ground product passes through \(0.5~\mathrm{mm}\) opening. If the power required to grind \(2~\mathrm{tonnes/h}\) of the feed material is \(3.8~\mathrm{kW}\), the work index of the material is \underline{\hspace{2cm}. (rounded off to 2 decimal places)}
During which of the following times of the day is the 2 m air temperature usually the lowest at a tropical location?
Potato slices weighing 50 kg are dried from 60% moisture content (wet basis) to 5% moisture content (dry basis). The amount of dried potato slices obtained (in kg) is ................. (Answer in integer).
Identify the gas composition (in percent) suitable for packaging cured meat under MAP (Modified Atmosphere Packaging) conditions.
Which of the following sequence of events occurs during formation of egg-white gel?
Assume: P\(_N\): Native protein; P\(_D\): Denatured protein; P\(_A\): Aggregated protein; P\(_G\): Protein gel.
Notation:
- \(\Delta\): heating,
- \(\nabla\): cooling,
- \(\rightarrow\): forward reaction,
- \(\leftrightarrow\): reversible reaction.
Which of the following is the most suitable flexible packaging laminate for dry fruits?
Identify the CORRECT sequence of operations for dressing of poultry.
Which of the following statement(s) is/are TRUE for a package of gamma-irradiated (7.5 kGy) whole chicken?
Which genus of bacteria does NOT have a cell wall?
Which of the following pigments does NOT have pro-vitamin A activity?
Identify the analysis that must be performed FIRST to judge ‘cleanliness’ of spice/herb powders.
If there is a delay in oil extraction after bran is separated from the brown rice, the quality of rice bran oil deteriorates. Identify the suitable CAUSE and EFFECT for the deterioration in oil quality.
Among the following, which is/are the process(es) that lead to generation of new fats from existing ones?
The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ................ (rounded off to 2 decimal places).
The crystallization of a polymer can only proceed in a temperature range limited to glass transition temperature (\(T_g\)) on the lower side and the equilibrium melting point (\(T_m^0\)) on the higher side. In a miscible polymer blend with only one component being crystalline, which option(s) correctly match(es) the Temperature conditions with Events? \[ \begin{array}{|c|c|} \hline \text{Temperature conditions} & \text{Events}
\hline P: T_g \text{ of amorphous component<crystallizable one} & 1: \text{Temperature range for crystallization becomes smaller}
Q: T_g \text{ of amorphous component>crystallizable one} & 2: \text{Crystallization is inhibited}
R: T_g \text{ of blend>} T_m^0 \text{ of crystallizable one} & 3: \text{Crystallization envelope (}T_m^0 - T_g\text{) is widened}
& 4: \text{Crystallization is favored}
\hline \end{array} \]
The heat of polymerization of ethylene is 25 Kcal/mol. The amount of heat generated during the polymerization of 5.6 kg polyethylene is .............. Kcal. (Round off to the nearest integer)
The density of an amorphous polymer is 0.77 g/cm\(^3\) and that of its crystalline counterpart is 0.99 g/cm\(^3\). The density of a semi-crystalline sample of this polymer is 0.88 g/cm\(^3\). Find the degree of crystallinity (on weight basis) of this semi-crystalline sample. (Round off to two decimal places)
Titration was used to determine the molar mass of two linear monodisperse polymers A and B. Both polymers have the same repeat unit and contain acid end-groups. - 10 g of polymer A titrated with 5 mL of 0.1 M alkali solution. - 5 g of polymer B titrated with 5 mL of 0.1 M alkali solution. - All alkali reacted with acid end-groups. Find the ratio of the molar mass of A to that of B. (Round off to one decimal place)
A unidirectional composite of a resin is prepared with continuous fibers, with volume fraction of fiber = 0.7. Moduli: resin = 9 GPa, fiber = 90 GPa. Sample breadth = 4 mm, thickness = 1 mm. Tensile strain = 0.5%. Find the tensile force applied on the sample. (Round off to nearest integer)
A rubber contains 70 wt% butadiene (molar mass = 54 g/mol), 20 wt% isoprene (molar mass = 68 g/mol), 5 wt% sulfur and 5 wt% carbon black. Assume that all the sulfur is present in crosslinks. If each sulfide crosslink contains an average of two sulfur atoms, the percentage of possible crosslinks that are joined by vulcanization is ........................%. (Round off to one decimal place)