White bread has a short shelf life thus the loses its desired charcteracteristics upon storage and its also subject to spoilage by fungi. To avoid this spoilage and increase shelf life the addition of different levels of acidulants (calcium propionate acetic acid and sorbic acid at 0.1 0.2 and 0.3%) were evaluated for their quality characteristics contributing with acidulants as well as their microbial shelf life during 12 days of storage. In addition the mathematical model (GAB and BET) were applied to study the storage condition of bread. From the experiment it was found that bread with calcium propionate addition had the highest specific volume and springiness followed by bread with acetic acid and sorbic acid adding. On the other hand bread contained sorbic acid had the highest density hardness chewiness and color values (L* a*b*) followed by acetic acid and calcium propionate addition in order. Bread contained calcium propionate had the longest shelf life (12 days) followed by bread with acetic acid (8 days) and sorbic acid (6 days) adding respectively. The increase in acidulants levels result in an increase of bread shelf life. From the sorption isotherm curves bread contained 0.3% calcium propionate had the highest monolayer moisture content indicating that it was the most effective against microbrial spoilage of white bread studied.

The study of vegetable-carved processing packed in hermetically sealed container for 5 types of plant e.g. carrot pumpkin radish green papaya and cucumber which carved into rose or leave shape and preserved in acidified-pickle (7.23% vinegar 64.81% water 0.81% salt 27.00% sugar and 0.15% lactic acid pH 3.27). The processing were conducted by sanitized carved-carrot pumpkin and radish in peroxyacetic acid solution (80 mg/l 3 min) or dipped in tap water (3 min) for green papaya and cucumber. Then all carved-vegetables were blanched in calcium chloride solution (0.5% 3 min) followed by preserved in acidified-pickle in plastic box with a lid and stored for 4 days at room temperature (25ºC). The results showed that pH and °Brix decreased during 4 days storage and showed obviously tended to equilibrium. However carved-radish and cucumber were spoiled by microorganisms as a film on the surface of pickle solution and gas bubble was occurred inside a container on 4th days of the storage. Hence carrot and pumpkin were used in the next experiment which preserved in preservative-added recipe (27.03% vinegar 27.03% water 0.9% salt 45.05% sugar and 200 ppm sodium metabisulfite pH 3.39) with hot-filled method in glass bottle. Treatment was compared with carved-vegetables preserved in acidified-pickle and kept at 4oC as the control. The pH of samples of pickle solution carved-vegetables and mixed-sample of both treatments showed lower than 4.6 and °Brix were gradually decreased during storage periods.The appearance of both treatments were maintain good and not different between treatments. Shelf-life of carved-carrot -pumpkin and -radish stored in hermetically sealed container was up to 7 days. Total bacteria count Escherichia coli yeast-molds were not exceeded than the standard limited by Ministry of Public Health and Staphylococcus aureus was not detected