Farklı gaz geçirgenliklerine sahip ambalaj malzemelerinin toz formda ezogelin ve şehriyeli tavuk çorbalarının kalitesi ve raf ömrü üzerine etkileri
Effects of packaging materials with different gas permeabilities on the quality and shelf life of commercial powdered soup mixes
Yazar: AYŞE MERVE CELLAT
Danışman: PROF. DR. GÜRBÜZ GÜNEŞ
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Gıda Mühendisliği Ana Bilim Dalı / Gıda Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Gıda Mühendisliği = Food Engineering
Dizin: Gaz geçirgenliği = Gas permeability ; Hazır gıdalar = Prepared foods ; Hazır çorba = Instant soup ; Raf ömrü = Shelf life ; Ürün kalitesi = Product quality

Özet:
Son zamanlarda tüketicilerde hazır gıdaya ilgi gün geçtikçe artmaktadır. Hazır toz çorbalar da bu ürünlerden biridir. Kolay taşınabilir ve pişirme açısında zaman kolaylığı sağlaması bu gıda ürünlerinin en önemli avantajlarındandır. Hazır çorba, kurutulmuş bileşenleri  içermekte olup, su aktivitesi 0,60 değerinin altında olması sebebiyle dayanıklı gıda sınıfına girmektedir. Bu sebeple genel olarak mikrobiyal bozulma tehlikesi oldukça düşüktür. Bunun yanı sıra bu gıda ürünlerinde kimyasal bozulmalar meydana gelmekte olup bunların içinde en önemli yeri yağ oksidasyonu almaktadır. Hazır çorbalar kurutma prosesinden geçirilen ürünler olup bozulmalara karşı oldukça dayanıklı ürünler olmasına karşın doğru ambalaj materyali seçmek gıdanın raf ömrünü ve maliyetini önemli ölçüde etkilemektedir. Ambalaj materyalinin geçirgenliği gıda ile çevre arasında madde geçişini dolayısıyla gıdanın raf ömrünü önemli şekilde etkilemektedir. Çalışmanın amacı farklı oksijen geçirgenilk özelliğine sahip üç farklı ambalaj materyalinin (1,3-17,1 arasında), hazır çorba ürünlerinin raf ömrüne etkisini araştırmaktır. 
Bu çalışmada farklı geçirgenlik özelliğne sahip üç farklı ambalaj materyali kullanılmıştır. Bu materyaller Ambalaj-1, Ambalaj-2 ve Ambalaj-3 olarak kodlanmış olup oksijen geçirgenliği sırasıyla 1.31, 17.07, 4.79 cm3/m2.gün'dür. Ambalajların su buharı geçirgenliğ oldukça birbirine yakın olup sırasıyla 2,29, 1,45 ve 1,81 g/m2.gün'dür. Çalışmada test ürünü olarak ezogelin çorbası ve şehriyeli tavuk çorbası ürünleri kullanılmıştır. Bir ticari firmanın kendi tesisinde dolum yapılan ve test ambalaj materyalleri ile normal atmosfer gazı altında ambalajlanan ürünler fakülteye getirilmiş olup farklı depolama koşullarında depolanmıştır. -15℃ depolama sıcaklığı taze kontrol örneklerini oluşturmakta olup, 25℃ depolama sıcaklığı ticari depo sıcaklığı ve 35 ℃'de depolanan örnekler ise hızlandırılmış test koşullarını temsil etmektedir. Ayrı ayrı gruplandırılıp, belirtilen şartlarda depolanan numuneler her 2 ayda bir çeşitli kalite özellikleri açısından analiz edilmiştir. Bunlar tepe boşluğu gaz analizi, renk analizi, nem analizi, oksidasyon için TBARS analizi ve duyusal analizdir. Çalışmada sonuç olarak Ambalaj-1 ve Ambalaj-3 ile ambalajlanan numunelerde tepe boşluğundaki oksijen oranı zaman içinde azalmış olup, karbon dioksit oranı artmıştır. Ambalaj-2 ile depolanan numunelerde ambalaj içi gaz konsantrasyonu önemli şekilde değişmemiştir.Ambalaj-1 ile depolanan ezogelin çorbası numuneleri rengini daha iyi muhafaza etmiştir. Şehriyeli tavuk çorbası  numunelerinde zaman içinde renkte koyulaşma görülmüştür. Hem ezogelin hem de şehriyeli tavuk çorbası numunelerinde nem içeriği, TBARS değeri ve duyusal özellikler önemli şekilde etkilenmemiştir.
Sonuç olarak yapılan analiz ve gözlemler ile 12 aylık depolama süresi içerisinde ambalaj materyalinin geçirgenliğinin 1,3 ve 17, 1 aralığında, test edilen ezogelin ve şehriyeli tavuk toz çorbası örneklerine etkisi önemli bulunmamıştır.

Abstract:
Recently demand of consumers in ready-made food products is increasing due to the development of technology, intense work tempo and women's involvement in business life. Powdered soup mixes are an important ready-to-cook food product that is packaged and marketed after drying, grinding and powdering various nutritional components. Ready-to-cook soups in the market; concentrated soups, frozen soups and ready (dried) powder soups are presented to the consumer in different forms. Dried powder soups are more preferred than other varieties due to their easy and cheap storage potential, portability and less space requirement in storage. Powdered soup mixes have a very low moisture content due to the drying of the ingredients. Their water activity is below 0.60 and they are a durable food product. Their quality and shelf life are often determined by chemical spoilage. Especially lipid oxidation has the most important place among these deteriorations. The selection of packaging material is very important for these foods to maintain their quality throughout their shelf life. Various packaging applications are applied in order to preserve the quality and keep the shelf life at the maximum level in powdered soups. In general, polyethylene/aluminum foil-based laminated packaging materials are widely preferred for packaging. Generally, powdered soup mixes maintain their durability for a long time in three-layer packages that protect against air, moisture and light without using preservatives. In particular, oxygen permeability is one of the most important permeability properties that affect oxidation reactions in products.
The aim of this study is to compare the performance of three packaging materials with different gas permeabilities on maintenance of various quality attributes of two commercial powdered soup mixes: 'Ezogelin' and 'Tavuklu Tel Şehriye'. 'Ezogelin' powdered soup mixes is a product that contains powdered red lentils, rice, flour, salt, dried onions and garlic, bulgur, spices and tomato powder. 'Tavuklu Tel Sehriye' powdered soup mixes is a food product that contains noodle, starch, dried chicken meat, parsley, vegetable juice concentrate, spices, dried onions and garlic. The products were packaged with 3 different packaging materials under the same production line in a commercial company. All of packaging materials were multi-layered and labelled as: Ambalaj-1, Ambalaj-2 and Ambalaj-3. The O2 transmission rates (OTR) of the packaging materials at 23°C were significantly different and determined as 1.3, 17.1 and 4.8 cm3/m2.day for Ambalaj-1, Ambalaj-2 and Ambalaj-3, respectively. The water vapour transmission rate of these materials were found similar: 2.3, 1.4 and 1.8 g/m2.day, respectively.  The products were stored under at -15°C (serve as fresh control) and 25°C (commercial condition) for 12 months, and at 35°C (accelerated condition) for 10 months. The samples, which were grouped separately and stored under the specified conditions, were analyzed every 2 months for various quality characteristics: package head-space gas composition, colour, moisture, TBARS, and sensory analysis. The data were subjected to analysis of variance (ANOVA) to determine the effects of packaging material, storage time, temperature and their interaction. If there was a significant difference between the groups, Tukey test was applied to compare the factor levels with each other.
Although the O2 and CO2 values in the headspace of the samples were initially measured at the same and close to the air atmosphere, they changed over time depending on the packaging material and temperature. In the samples packaged with Ambalaj-1, a significant decrease in O2 in the headspace and an increase in CO2 were observed. In the Ambalaj-3 samples, on the other hand, there was less change in the headspace gas ratio compared to the Ambalaj-1 material depending on time, while no significant change was detected in the Ambalaj-2 packaged samples. The O2 ratio in the headspaces of the samples in Ambalaj-1 and Ambalaj-3 materials was significantly reduced over time. Compared to the initial measurement, the Ezogelin samples packaged with Ambalaj-1 and Ambalaj-3 showed a decrease of 5.2% and 4.2%, respectively, at room temperature at the end of 12th month. At room temperature the CO2 rate  was measured as 1.5% in the samples using Ambalaj-1 and 0.9% in samples using Ambalaj-3 at the 12th month in 'Ezogelin' samples. While the headspace O2 ratio of the samples in Ambalaj-1 decreased by 2.8% compared to the samples measured at the beginning of storage, the O2 ratio of the samples in Ambalaj-3 decreased by 2.1% in 'Tavuklu Tel Sehriye' samples in room condition.  At the end of 12 months in the 'Tavuklu Tel Sehriye'samples, the CO2 ratio was 0.8% in the Ambalaj-1 and 0.4% in the Ambalaj-3.
The change in the package headspace gas ratio is related to the gas permeability of the packaging material and the biochemical reactions in the products. The color change that occurred in all samples over time was investigated by visual, instrumental and sensory analysis and according to the results of these, it was determined that the 'Ezogelin' soup samples in the Ambalaj-1 preserved their color better. In accelerated conditions, it was understood that the color of the chicken noodle soup packaged in Ambalaj-3 darkened more depending on time compared to the samples in the other packaging material. When the moisture content and clumping of all samples were examined, there were no significant differences among the samples stored in different packages. According to the results of the TBARS analysis to determine the oxidation level, the periodically measured TBARS values of the samples were not significantly affected by the packaging material. At the end of the storage period, an increase was detected in TBARS value of 'Ezogelin'  (3.9 to 8.2 µmol/g) and 'Tavuklu Tel Sehriye (1.6 to 2.5 µmol/g) stored at room temperature. When the sensory analysis results were evaluated, although a 1-2 point decrease was detected in the scores of the samples depending on time and temperature, the differences due to packaging were not statistically significant.
In the accelerated conditions, the increase in TBARS value higher. In the sensory evaluation, no significant differences were detected among the packaging materials and it was concluded that the flavor and general quality of the soup samples were not affected by the packaging materials tested in the research. Different levels of changes were determined in different quality criteria during storage at 35°C, which was applied as the accelerated shelf life test condition. However, according to the sensory analysis made on overall atrtributes, the samples were still acceptable for consumption after 10 months of storage.
In conclusion, use of packaging materials with different OTR from 1.3 to 17.1 cm3/m2.day resulted in similar quality of the products during 12-month storage. Thus selection  of packaging material within this OTR range can be based on their cost and other relevant attributes.  However, if a shelf-life more than 12-month is desired further researches are required to evaluate the performance of these packaging materials in maintaining quality.