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An IR spectroscopic investigation of tarhana

*Corresponding author
1. Faculty of Arts and Sciences, Physics Department, Mehmet Akif Ersoy University, Burdur, 15030, Turkey
2. Accademia di Agricoltura di Torino, Via Andrea Doria, 10, Torino 10100, Italy.


Tarhana is a popular Turkish fermented wheat-yogurt mixture for soup making. This traditional food is widely consumed in Turkey. In the last decades, tarhana has been produced commercially in factory. Ingredients of tarhana both homemade and fabricated are display variations. Quality control of tarhana is becoming a problem. The IR spectra of 12 commercial (COM) or home-made (HM) samples were investigated. The T% values were constantly inferior in the HM (-15%) sign of a richer content. Along the spectra from 4000 to 400 cm-1 the F fisher’s test of single wavelength differentiated maximally the two types at 402 cm-1(P=0.23), but a wavelength selection process clusterized 6 bands (2476, 1596, 1364, 608, 596, 402 cm-1). A multiple regression was developed on the six bands in a discriminative equation provided by a R2 0.92 (R2adj 0.83). After full cross-validation the R2 values descended to 0.65, but only 1 sample of COM type was missed as HM. Some hypothesis concerned the implicated bands in regards to a different vitamin B3 (Niacine) contents. IR spectroscopy is a useful tool to identify a sample due to its unique results. FTIR Spectra results show that vibrational frequencies can be specific data to confirm the quality and traceability of tarhana.


One of the oldest traditional Turkish soups, tarhana has been locally consumed for many generations. Products similar to “Tarhana” in Turkey are known as the Cypriot “Trachanas”, “Kishk” in Egypt, Syria and Jordan, “Kushuk” in Iraq and “Tahonya/Talkuna” in Hungary and Finland (1). The protein and vitamin contents of tarhana make it one of the most important foods (2-4). Also, in the folk culture, it is believed that tarhana cures some basic illnesses (like sore-throats, stomach-aches, colds and flues) Methods for preparation and amount of ingredients may vary from one place in Turkey (5, 6). A great deal of attention has been paid towards healthy foods; therefore there is a growing commercial interest in producing tarhana. In addition to that, tarhana has got a 2-3 years shelf life (7). This fact encourages producers in food industry.
Promoting tarhana industrial production is risky, because consumers demand nutritious and healthier food. Rapid quality control of tarhana has become a serious problem. The microbiological, physical and chemical hazards have been examined by scientists (7-10)
IR spectroscopy ...