## 8 Bromelain, Ficin, and Papain Peels By-Products-Based Cosmetic Applications
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Aspect/Feature \({}^{*}\)**} & \multicolumn{4}{c}{**Proteolytic Enzyme**} & \multirow{2}{*}{**References**} \\ \cline{3-4}  & & **Bromelain** & & **Ficin** & **Papain** \\ \hline \multirow{6}{*}{Potential Side Effects} & \(\bullet\) & Skin rashes, itching, swelling, and more severe reactions & & & \(\bullet\) & May cause rashes, itching, contact dermatitis, and allergic reactions, & \\  & & those with pineapple & particularly in those & & \(\bullet\) & Kerainolytic activity \\  & & allergies & sensitive to fig latex & & degrades tight junction \\  & & It can also cause & & High prevalence of & proteins, increasing skin \\  & & false-positive latex skin prekets & & cross-sensitization with & permeability \\  & & May be cross-reactive with & & fig byproducts and birth & \(\bullet\) & People with sensitive skin \\  & & other allergens such as latex, & pollen allergens & may be more prone to & \\  & & papain, or wheat flour & & reactions & \\ \hline \multirow{6}{*}{Stability} & \(\bullet\) & Stable at pH 5.0 for extended & & & \\  & periods, and activity is able to increase up to pH 7.0 & & Less active under acidic conditions, unstable at & Stable at a broad range of temperatures, better at a neutral pH & \\  & & Inactivated at pasteurization & low pH & & neutral pH \\  & & temperature, retains activity & \(\bullet\) & Retains \(>\)50\% activity & \(\bullet\) & Active at 10-90 \({}^{\circ}\)C but \\  & & At 40–60 \({}^{\circ}\)C & between 40 and 70 \({}^{\circ}\)C & & loses stability over time & [35; 44; 57; 69; 90; 91; 97; 98; 101; 107; 133] \\  & & Loss activity when heated & & Denatures above 70 \({}^{\circ}\)C & & Rapid loss of activity at \\  & & at 100 \({}^{\circ}\)C for 10 min & & & 90 \({}^{\circ}\)C & \\  & Stable at 4 \({}^{\circ}\)C, retains & & Moderate stability at & & Stability increases when \\  & stability for long periods at & & low temperatures & & immobilized \\  & & –20 \({}^{\circ}\)C & & Influenced by autolysis, & & Influenced by oxidation, \\  & & Influenced by pH, & metal ions, and pH & & inhibitors, and formulation \\  & temperature, and exposure & variation & & conditions & \\  & to surfactants & & & & \\ \hline \multirow{6}{*}{Major Stabilizers and Inhibitors} & \(\bullet\) & Stabilizers: prekets, & & & Stabilizers: PEG, \\  & & chitosan nanoparticles, & & sorbitol, sucrose, xylitol, & SC-glucan, EDTA, cysteine, \\  & & Na\({}_{2}\)SO\({}_{4}\), CaCl\({}_{2}\), & & TPP, immobilization & encapsulation in cream or \\  & lyoprotectants like maltose & & & & gel formulations \\  & and cream–gel formulations & & Inhibitors: E-64, Zn\({}^{2+}\), & & Inhibitors: heavy metals, \\  & & Inhibitors: heavy metals & non-optimal pH, & & oxidation, \\  & & (Ag\({}^{+}\), Hg\({}^{+}\), Cu\({}^{2+}\)), & & & alpha-1-antitrypsin (AAT) & \\  & & iodoacetate, anhydrous gels, & & & \\  & oxidation & & & & \\  & & affected by pH and & & & \\  & & & vice versa & & \\ \hline \hline \end{tabular}  
* General profile, characteristics, properties, cosmetic efficacy, and sustainability. Overall, some significant data concerning the proteolytic activity of bromelain, fiction, and papain from fruit peel by-products and their potential applications in functional cosmetics defined for skincare must be examined. Bromelain, fiction, and papain are cysteine proteases with distinct specificities, impacting their dermatological applications, effects on skin types, allergic reactions, and their potential within a circular economy.  
\end{table} 
Table 4: _Cont._reducing melanin synthesis and improving skin tone [70; 147; 152; 183]. All proteolytic enzymes displayed vast anti-inflammatory, antioxidant, antimicrobial, anti-thrombotic, and wound healing properties, displaying both great similarities and differences in their specific activity. Enzymatic exfoliants provide a milder option compared to chemical ones, making them ideal for sensitive skin; however, individual sensitivities may still arise.