EFFECT OF LOW TEMPERATURE STORAGE FOR UNCOOKED SALA LAUAK.

Vioni Derosya and Netty Sri Indeswari. Department of Agricultural Product Technology, Faculty of Agricultural Technology, Andalas University, Kampus Unand Limau Manis Padang 25163, Indonesia. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 16 August 2018 Final Accepted: 18 September 2018 Published: October 2018


ISSN: 2320-5407
Int. J. Adv. Res. 6(10), 1349-1355 1350 Today, sala lauak is sold in different ways. Consumer can buy sala as a ready-to-eat snack on street vendors or people buy sala lauak flour. Sala lauak flour is made from rice that soaked for one night and spices that mixed together and processed into flour then roasted. However, making fresh sala lauak from scratches or sala lauak flour is not simple. To make sala lauak from sala lauak flour, it still needs additional ingredients such as dried fish and spices as explained by Kamsina and Anova (2011). This condition gives an idea for home industries to produce and sell uncooked sala which is rounded sala dough. This dough only needs to be fried before serving. Uncooked sala is preferable to consumers since it can be cooked at home, served directly after frying and healthier than those fried sala lauak in the market.
Unfortunately, uncooked sala has a short shelf life. The packaging of uncooked sala uses only mica plastic for 20-30 rounded sala dough. Based on a survey of sellers in by Handayani et al. (2017), quality of uncooked sala only maintain for 12 hours. Since uncooked sala has a short shelf life, the producer cannot answer many demands particularly during Ramadhan and Eid Fitri Celebration. Around this two months, people from other cities in Indonesia back to kampung to have a family celebration and eat traditional food such as sala lauak. In addition, they want to bring back sala lauak as snack or souvenir at the end of the holiday. The producers of uncooked sala rejected demands from other cities in Indonesia that required 3-4 days to be delivered. Demands actually come from West Sumatera people live in other cities but they want to eat this traditional dish. The condition of market demand for uncooked sala is an opportunity for home industries to expand their productivity. Thus, development in process production and technology utilization are needed in optimizing added values from this local product.
Previous research mainly related to variation and addition ingredients of sala lauak. Kamsina and Anova (2011) observed the quality of different flour and fish processing for sala lauak while Febriana et al. (2014) used different kind of rice flour to make sala lauak. Next, Sari et al. (2013) explored different varieties of fish and rice flour for sala lauak as a snack for autistic patient. For applying technology for uncooked sala, there is still inadequate study on sala lauak particularly uncooked sala and its change during storage. It is important to understand the quality change during storage such as appearance, nutrition content, and food safety in order to apply technology for product development.
Low-temperature storage was used to maintain quality of fruit, vegetables and food products. Low temperature storage such as refrigerator is a basic and affordable white goods appliance in a household (Mcneil & Letschert, 2010). Refrigerator storage was utilized by Kung et al. (2017) for control hazardous level of histamine on milk-fish sticks and to prolong the shelf-life of tempeh bacem (boiled tempeh with spices) (Rochim, 2014), and surimi from mixed fish by Jannah (2012) & Harahap (2012). Thus, storing uncooked sala at low temperature might prolong its shelf life. This study was observed on quality changes during low temperature storage compared to those in room temperature.

Materials and Methods:-
Uncooked sala was obtained from local market in Padang area, Indonesia at the same day with production day. Samples were packed in PP plastic and sealed using hand sealer. Then, samples were put in room temperature at 26-30ºC and refrigerator at 10ºC.
The moisture and ash were conducted using weight difference method. Fiber content was determined from the loss in weight of the crucible and its content on ignition. Carbohydrate was analyzed by summing of the percentage of moisture, ash, crude protein either extracts and crude fibers were substracted from 100. The nitrogen value as protein precursor from a substance was analyzed by micro Kjeldahl method involving sample digestions, distillation and titration. All the proximate values were reported in percentage using AOAC method.
For Total Plate Count (TPC), five grams of sample of uncooked sala for each treatment was serially diluted four times to obtain a 1:10 4 dilution, spreaded on plate and incubated for 24 hours. Next for hardness, texture analyzer was utilized with cylinder probe and speed at 1.5 mm/s. Color meter (Hunter Lab Color flex) was used to observe L, a, and b value of sample then Hue and Chroma can be calculated.
Statistical analyses were conducted using SPSS 16.0 for Windows (SPSS Inc., Chicago USA). In this study, significant effects of storage condition (p<0.005) were observed based on Duncan's range tests.

Results and Discussion:-
There is a possibility of chemical changes to occur during storage leads to food deterioration including reducing quality of nutritional quality . Thus, chemical changes were analyzed based on proximate analysis in 6 days of observation. From proximate analysis, water content was observed for both room and refrigerator as shown in Table 1.  2012) noted that water content in food product with oily content affect shelf life of products since it is related to rancidity and oxidation process. As the result, water contents for uncooked sala in room temperature are between 68.01 % and 74.27 % which was significant difference per day during observation. Further, a significant difference on level p = 0.005 was also noted from water content of uncooked sala in refrigerator. The values were between 68.01 % and 70.45% which were lower than those kept in room temperature. However, there is no significant change on water content between uncooked sala in room and uncooked sala in refrigerator as shown in Table 1. Further, it can be inferred from this analysis that uncooked sala has a relative high even it is kept on refrigerator. A proper packaging and store are required since high water content is related to vulnerability food products.
Uncooked sala in both storage conditions were observed in 6 days for ash component. Ash is remained inorganic components in food products (Nielsen, 2010). Ash from uncooked sala is related to inorganic compound such as from dried fish, rice and spices. Ash of uncooked sala in room temperature was about 1.23% to 1.84% while those in refrigerator was about 1.21-1.86% of ash. Initially, ash was about 1.38% and change with no significant value at p=0.05 per day of storage period in both storage conditions. However, there was a significant difference on ash content between uncooked sala kept in room and those in refrigerator on which ash content of uncooked sala from room temperature was higher than those from refrigerator.
Next, protein analysis was conducted using the Kjeldahl method. Nielsen (2010) noted that nitrogen is the major distinctive factor of protein. Protein analysis using this method is basically counting all organic nitrogen from material. Initially, protein content of uncooked sala was about 1.91% as shown in Table 2. Protein content of uncooked sala kept in room temperature was significantly difference with those in refrigerator. Although there was no significant change in protein content per observationday, protein reached the highest value on the 3rd day observation which were 1.87% in room temperature and 2.03% in refrigerator. It might related to microorganism activities that still high and counted as protein too. At the end of observation, protein of uncooked sala were 1.44% in room temperature and 1.65% in refrigerator.
Fat component of uncooked sala was also analyzed during 6 days observation. Fat in food products as explained by Nielsen (2010) is included phospholipids and triacyl glycerols which named oils at room temperature or fat if it is solid in room temperature. At the first day of observation, uncooked sala has 0.05% of fat content. Similar to protein content, there was insignificant increase on 3rd day observation for fat before decreasing. However, uncooked sala in room temperature and refrigerator has significant difference. Uncooked sala in room temperature has between 0.05% to 6.2% while those in refrigerator has between 0.05% to 5.73% as shown in Table 3.
Qualitative and quantitative analysis for carbohydrates is to determine food product composition and also product characteristics (Nielsen, 2010). Carbohydrate by difference was calculated for uncooked sala in 6 days observation as shown in Table 4. There was 28.66% of carbohydrate (by difference) in uncooked sala initially. No significant difference on carbohydrate of uncooked sala during observation days but the different was significant at p = 0.05 for 1352 carbohydrate of uncooked sala in room temperature to those in refrigerator. Carbohydrate of uncooked sala from refrigerator was higher than those from room temperature might indicate that microorganism use more carbohydrates for its growth in room temperature.   Beside proximate analysis, color changing was analyzed since it is easily change people perspective in purchasing product. Based on °Hue and Chroma number, color of uncooked sala is classified as yellow-red as stated in Hutching (1999). The yellow color of uncooked sala comes from turmeric as explained by  Table 5. Samples in this study were packaged in polypropylene (PP) plastic then be sealed. PP, as noted by Brennan (2006), is a product of low-pressure polymerisation of propylene using catalyst. PP has a low permeability to water vapour and gases. PP is usually coated with PE or PVC to make it heat-sealable and to improve its properties. Physical changes and defect such as mucus can be observed from packaging using PP.
Defect on food product happened as the result of environment, oxygen, humidity, temperature change followed by changing on texture, color, and mucus on product surface because of microbiological (Habibah & Aminah, 2004). Total Plate Count (TPC) was conducted to obtain information about general microbiological activity in uncooked sala during storage in room temperature and the refrigerator. The result of TPC is defined as colony forming units (CFU) to estimate the present number of cells as colony. In counting colonies, there are named general ranges as common acceptance for countable numbers of colonies on a plate which are 30-300. The upper limit per plate which is 300 is related to competition of colonies for space and nutrients (Sutton, 2011). At the initial day of storing, it was found that uncooked sala lauak was already containing 7.2 x 10 5 cfu. Next, too numerous too count was detected on the first day for sample from room temperature storage. For samples that kept in refrigerator, TNTC was found after the third day of storage. Further, the mucus was found from both storage condition samples along with reducing value of samples hardness on the first 3 days. It might be related to condition where too numerous to count (TNTC) of total plate count after 3 days in refrigerator and after the first day for those in room temperature.
During packaging, microorganism can spread as the results of poor packaging and storing. Using packaging with high permeability to gas and water vapour takes a risk since microorganism contine to grow and increase the number during storage (Forsythe & Hayes, 1998). Further, contents of food product are supporting bacteria and fungi to grow. Food with high protein content is easily become a suitable growth area for Staphylococcus aureus that was identified causing toxicity by producing enterotoxin. At the very worst, enterotoxin from S. Aureus is heat resistant although after heating at temperature 100°C for 30 minutes (Balia et al., 2013).
In addition, Marth (1998) noted in extended storage using refrigerator that psychrotrophic and mesophilic pathogens might still grow. There are many food products that already contaminated from initial production process such as raw material handling even during processing, storage and distribution. In this study, uncooked sala lauak had 7.2 x 10 5 cfu as the result of total plate count. Thus, the preventive control such as good manufacturing practices (GMPs), sanitation and hygiene have important contribution to the shelf life of uncooked sala lauak.  3  TNTC  TNTC  4  TNTC  TNTC  5  TNTC  TNTC  6 TNTC TNTC Next, we also conducted test for hardness of uncooked sala during storage in room and refrigerator. Initially, the hardness of uncooked sala was 170.25 gram force as shown in Figure 1. After the first 3 days of storage time, it was found that uncooked sala become harder particularly those in refrigerator. The hardness of uncooked sala from refrigerator after 3 days in storage was 260.25 gram force which was higher than those from room temperature (129.75 gram force). This unfavorable condition related to caking on amorphous component of rice flour as one of main components in sala lauak. As explained by Bhandari (2007), amorphous component is vulnerable temperature changing and humidity. 1354