QUALITY MAINTENANCE OF GREY OYSTER MUSHROOM (PLEUROTUS OSTREATUS) BY NANOSILVER PACKAGING AND ETHYLENE ABSORBERS

Grey oyster mushroom (Pleurotus ostreatus) is widely cultivated and consumed as food in Malaysia. Mushrooms continue to respire after harvest and they have a relatively high respiration rate compared to other fresh produce. It is necessary that they are either marketed soon after harvesting or preserved with special care such as in cold storage or other controlled environment storage. Therefore, the present study aims to assess the effect of ethylene absorber and nanosilver packaging on quality of grey oyster mushroom. Grey oyster mushroom was harvested at 5 days after emerging with the cap diameter 75-80 mm. The quality of grey oyster mushroom was evaluated after packing in 3 different packages i.e., (1) CFB boxes lined with 0.04 mm LDPE as a control, (2) CFB boxes lined with 0.04 mm LDPE with added six sachets of ethylene absorber, and (3) CFB boxes lined with 0.04 mm LDPE containing 1% nanosilver. In all the packaging, water absorbers were added to absorb moisture during storage. Mushroom was stored at 2°C and evaluation was carried out at 0, 5, 8,12, 15, 19 and 22 days of storage. Postharvest quality evaluation included physical (visual appearance, weight loss, colour of cap and gill; L, hue, chroma), chemical (pH, TSS, TTA, ascorbic acid) and gases (O₂, CO₂, C₂H₄). Ethylene absorber did not result in significant changes in most of mushrooms quality parameters evaluated (TSS, ascorbic acid, O₂, CO₂, colour of cap and gill; L, hue, chroma). However, ethylene absorber significantly (p<0.05) increased acidity of grey oyster mushroom (reduction of pH and increased of TTA). Nanosilver packaging did not affect the variables studied except increasing chroma of gill. Visually, mushroom packed in nanosilver packaging was yellowing rapidly and the surface looked dry compared to other packaging. Grey oyster mushroom can be stored until 22 days at 2°C packed in 0.04 mm LDPE with added ethylene absorber compared to 19 days in nanosilver packages and 12 days for control.