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Ultrasound processing is a non-thermal technology that uses sound waves at a high frequency of 20 kHz–10 MHz. The number of its applications in the food industry is increasing as this technology offers a more efficient and convenient alternative or aid to conventional food processing techniques. The utilization of ultrasound in the processing of cereals, including the extraction of functional components, germination, hydration, fortification, and hydrolysis in the cereal foods sector is promising. Ultrasound-assisted food processes such as the mixing of doughs and batters, cutting/portioning, and fermentation are also gaining the interest of bakery and snack food producers. Moreover, the technology provides a rapid and online monitoring tool for the control of food processes. This chapter discusses the basics of ultrasound technology and systems, its benefits for food processing, and the applications of ultrasound-assisted technologies in the processing of cereals and bakery and snack foods.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, where social and communication deficits and repetitive behaviors are present. Plant-derived bioactives have shown promising results in the treatment of autism. In this sense, this review is aimed at providing a careful view on the use of plant-derived bioactive molecules for the treatment of autism. Among the plethora of bioactives, curcumin, luteolin, and resveratrol have revealed excellent neuroprotective effects and can be effectively used in the treatment of neuropsychological disorders. However, the number of clinical trials is limited, and none of them have been approved for the treatment of autism or autism-related disorder. Further clinical studies are needed to effectively assess the real potential of such bioactive molecules. Portuguese Foundation for Science and Technology under the Horizon 2020 Program [PTDC/PSI-GER/28076/2017] N.C.-M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017).

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015, Thesis (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2015, Baharatlar, gıdaların renk ve lezzetini artırmak amacıyla dünya mutfaklarında sıklıkla kullanılmaktadır. Baharatların mikrobiyolojik açıdan çok yüksek kontaminasyona sahip olmaları eklendikleri gıdaların güvenliği açısından sorun yaratabilmektedir. Dolayısıyla baharatların uygun yöntemlerle sterilize edilmeleri gerekmektedir. Gama ışınlama baharat sterilizasyonunda en çok kullanılan yöntemlerden biridir. Ancak, ışınlama çeşitli gıdalarda oksidasyon ve renk kaybı gibi istenmeyen yan etkilere yol açabilmektedir. Bu yan etkilerin azaltılmasında ışınlamanın modifiye atmosferde ambalajlama (MAA) ile birlikte kullanımı etkili olabilmektedir. Çalışmanın ilk bölümünde toz formdaki kekik (Thymus vulgaris), biberiye (Rosmarinus officinalis), karabiber (Piper nigrum) ve kimyon (Cuminum cyminum) hava (aerobik ambalajlama, AA) veya %100 N2 (%0 O2, modifiye atmosfer ambalajlama, MAA) ile ambalajlanmış ve 7 kGy, 12 kGy ve 17 kGy dozlarda ışınlanmıştır. Kontrol olarak ışınlanmamış örnekler kullanılmıştır. Örnekler mikrobiyal kalite, renk ve uçucu yağ verimlerine göre değerlendirilmiştir. Uçucu yağ profilindeki değişimler GC-MS ve iki boyutlu gaz kromatografisi (GC×GC-FID ve GC×GC-Q-TOFMS) ile incelenmiştir. Gama-ışınlamanın mikrobiyal yükü azaltmada tek başına yeterli olduğu, ancak MAA ile birlikte kullanımının bazı avantajlar sağladığı görülmüştür. Küf-maya ve toplam mezofilik aerobik bakteri sayımları sırasıyla 7 kGy ve 12 kGy ışınlamadan sonra 1 log kob/g seviyesinin altına düşmüştür. Işınlama biberiye ve karabiberde renk kaybına neden olmuş, ancak MAA’nın karabiberdeki renk kaybını azalttığı görülmüştür. Karabiber ve kimyonun uçucu yağ verimleri MAA’da daha yüksek ölçülmüştür. Modifiye atmosferde ambalajlanan örneklerin monoterpen içeriklerinin daha yüksek, oksijenli bileşen ve seskuyiterpen içeriklerinin ise daha düşük olduğu görülmüştür. Ayrıca, modifiye atmosferde ambalajlanan örneklerin uçucu yağ bileşenlerindeki azalmanın daha düşük olduğu görülmüştür. Uçucu yağ bileşenlerindeki değişim ayrıca GC×GC analizi ile de incelenmiş, 2 boyutlu kromatogramlar sayesinde ışınlama sonrasında bazı yeni piklerin oluştuğu ya da mevcut piklerin miktarında artış olduğu görülmüştür. Bu piklerden üç tanesinin üzeride durulmuş ve bunlardan ikisi GC×GC-Q-TOFMS ile 4-(1-methylethyl)-1,3-cyclohexadiene-1-methanol ve 2-caren-10-al şeklinde yaklaşık olarak tanımlanmıştır. Diğer pikin ise miktarında artış görülmüş ve GC×GC-FID ile dış standart kullanılarak kuminaldehit olarak tanımlanmış, TOFMS ile de doğrulanmıştır. Elde edilen bu piklerin tek boyutlu GC ile de elde edilebilmesinin neredeyse imkansız olduğu ve GC×GC yönteminin bu tür örneklerin analizinde avantaj sağladığı görülmüştür. Çalışmanın ikinci bölümünde ise söz konusu baharatlar hava veya modifiye atmosfer ortamında ambalajlandıktan sonra 6 kGy ve 14 kGy dozlarda ışınlanmış, ışınlanmayan örnekler ise kontrol olarak kullanılmıştır. Uçucu yağlar ve metanol ekstraktları elde edildikten sonra ışınlama ve MAA’nın toplam fenolik madde içeriği, DPPH radikal yakalama aktivitesi, FRAP ve %AA (β-karoten-linoleik asit testi) değerlerine etkileri incelenmiştir. Ayrıca uçucu yağ ve ekstraktların Bacillus cereus, Escherichia coli, Staphylococcus aureus ve Aspergillus niger mikroorganizmalarına karşı minimum inhibisyon konsantrasyonları (MİK) incelenmiştir. Işınlamanın uçucu yağ ve ekstraktların antioksidan ve antimikrobiyal aktivitesini genellikle artırdığı görülmüştür. Karabiber uçucu yağı ve kimyon ekstraktının toplam fenol içeriği ışınlama ile artarken, biberiye uçucu yağında azalmıştır. Biberiye, karabiber ve kimyon uçucu yağları ile kekik ekstraktının DPPH yakalama aktivitesi ışınlama ile artış eğilimi göstermiştir. Baharat ekstraktlarının FRAP değerlerinde de artış görülmüştür. Karabiber uçucu yağının %AA değerlerinde ışınlama ile artış, kimyon uçucu yağında ise azalma gözlenmiştir. Aerobik ambalajlanmış örneklerin antioksidan değerleri genel olarak MAA uygulanmış örneklerden daha yüksek bulunmuştur. Kekiğin uçucu yağ ve ekstraktının antioksidan aktivitesinin diğerlerinden daha yüksek olduğu görülmüştür. Kekik ve kimyon başta olmak üzere baharatların antimikrobiyal kapasitelerinde artış kaydedilmiştir. İncelenen mikroorganizmalar arasında A. niger’in uçucu yağlara en hassas olduğu görülmüştür. En hassas bakterinin ise S. aureus olduğu görülmüştür. Çalışmanın son kısmında ise hava veya MAA (%100 N2) altında ambalajlanan baharatlar 6 ve 14 kGy dozda ışınlanmış ve altı ay boyunca oda sıcaklığında depolanmıştır. Işınlama ve MAA’nın depolama sırasında mikrobiyal kalite, renk değerleri, duyusal özellikler, uçucu yağ verimi ve uçucu yağların antioksidan (toplam fenolik madde içeriği, ,2-difenil-2-pikrilhidrazil (DPPH) radikal yakalama aktivitesi, demir indirgeyici antioksidan gücü (FRAP) ve β-karoten-linoleik asittesti) ve antimikrobiyal aktivitesine etkileri incelenmiştir. Çalışmanın ilk kısmında olduğu gibi ışınlama depolama öncesi ve sonrasında mikrobiyal kalitenin korunumunu sağlamıştır. Renk kaybının depolama sırasında arttığı görülmüştür. Işınlamaya bağlı olarak da renk değişimlerinin olduğu ancak bu etkinin depolama sırasında ortadan kalktığı görülmüştür. Genel olarak, uçucu yağ verimi, toplam fenol içeriği, DPPH yakalama aktivitesi ve antimikrobiyal aktivite depolama sırasında azalmıştır. FRAP ve %AA değerlerinde ise depolama sonunda artış görülmüştür. Depolama başlangıcında ışınlama dozu ve ambalaj çeşidine bağlı olarak görülen değişimlerin depolama sonunda yok olduğu görülmüştür. Sonuç olarak; kekik, biberiye, karabiber ve kimyonun ışınlama işleminden önce modifiye atmosferde ambalajlanması ile renk ve uçucu yağ içeriğinde görülen azalmaların önleneceği söylenebilir. Ayrıca elde edilen sonuçlar, GC×GC yönteminin baharatlarda ışınlamanın tespit edilebilmesi adına kullanılabileceği yönünde umut vericidir. Baharatların duyusal özellikleri ışınlama, modifiye atmosferde ambalajlama ve depolamaya bağlı olarak genellikle değişim göstermemiştir. Işınlama, özellikle aerobik ambalajlanmış baharatları uçucu yağ ve ekstraktlarının antioksidan, modifiye atmosferde ambalajlanmış örneklerin ise antimikrobiyal aktivitelerini artırma eğilimi göstermiştir. Depolama çoğu kez uçucu yağ verimi, antioksidan ve antimikrobiyal aktivitede azalmaya yol açmakla birlikte, depolama başlangıcında ışınlama ve ambalaja bağlı değişimlerin zamanla ortadan kalktığı görülmüştür., Spices are widely used in food recipes all over the world in order to enhance the color and flavor. Unfortunately, these products are very prone to microbial contamination and threat the safety of the food they are added. Thus, a proper sterilization method, such as gamma irradiation should be used. Even though gamma irradiation is one of the most used methods in spice sterilization, it can result in oxidation and color loss in the food. Combination of irradiation with modified atmosphere packaging (MAP) can decrease the undesired effects of irradiation. In the first part of the study; thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), black pepper (Piper nigrum) and cumin (Cuminum cyminum) in ground form were packaged under either ambient atmosphere (aerobic packaging, AP) or 100% N2 (0% O2, modified atmosphere packaging, MAP). Packaged samples were irradiated at 7 kGy, 12 kGy and 17 kGy doses in an irradiation facility. Non-irradiated samples were used as control. Samples were evaluated according to their microbial quality, CIELAB color values (L*, a*, b*) and essential oil yield. Changes in the essential oil profile was evaluated by one-dimensional gas chromatography-mass spectrometry (GC-MS) and two-dimensional comprehensive gas chromatography (GC×GC-FID and GC×GC-Q-TOFMS). Gamma-irradiation alone was sufficient to decrease the bacterial load; however, the combination of irradiation with MAP was advantageous. Total mesophilic aerobic count and yeast-mold count were decreased to below 1 log cfu/g after irradiating at 12 kGy and 7 kGy, respectively. Irradiation caused color loss in rosemary and black pepper, bu the application of MAP decreased the irradiation induced color loss in black pepper. The essential oil yield of black pepper and cumin were higher in MAP compared to AP. Thyme essential oil was mainly characterized by carvacrol, and rosemary essential oil was characterized by 1,8-cineole, α-pinene and verbenone, respectively. The major compounds in black pepper were β-caryophyllene, δ-3-carene and valencene. Cumin essential oil was mainly characterized by cumin aldehyde, γ-terpinene and safranal. Gamma-irradiation and O2 content of the packages had varying effects on the essential oils of the spices. The changes in essential oil profile of aerobically packaged samples were higher compared MAP. The monoterpene content in the essential oils of the modified atmosphere packaged samples were higher, whereas oxygenated component and sesquiterpene content were lower compared to aerobically packaged samples. The changes in essential oil content were lower in samples packaged without O2. Differences in essential oil content were also evaluated by GC×GC analysis, and better separation and visualization were achieved by 2D contour plots of new components produced after irradiation. Two of the peaks emerged after irradiation of air-packaged (AP) samples at all doses (7, 12 and 17 kGy). These peaks were tentatively identified as 4-(1-methylethyl)-1,3-cyclohexadiene-1-methanol (CAS number 1413-55-4), and as 2-caren-10-al by using GC×GC accurate-mass time-of-flight mass spectrometry (TOFMS). In addition, a third peak increased in relative abundance after irradiation of the AP samples, and it was identified as cumin aldehyde by using a flame-ionization detector (FID) through comparison with an external standard and also confirmed by TOFMS identification. Although these changes were almost impossible to be noted in 1D GC, GC×GC made more detailed analysis and more reliable comparison of samples possible. It can be said that comprehensive two-dimensional gas chromatography is a useful technology for the comparison of samples with minor differences and where potential volatile molecular changes in samples might not be known in advance. In this specific case, it will be valuable in future studies to detect the irradiation treatment of spices, or by extension, comparison of other samples through their volatile profiles. As the compounds that were the focus of this study were only detectable as resolved peaks in GC×GC, it can be used in the detection and separation of these components in other studies with essential oils. It was observed that irradiation in the presence of oxygen may produce a number of new compounds, or alters the amount of existing compounds in the essential oils of spices. Some of the changes are initiated by oxidation under the effect of irradiation. The extent of changes in compounds attributable to oxidation were significantly lower or in some instances not detected in samples packaged under modified atmosphere. In the second part of the study; the spices (thyme, rosemary, black pepper and cumin) in ground form were packaged aerobically or under 100% N2 (MAP). Packaged samples were irradiated at 6 kGy or 14 kGy doses. Control samples were not irradiated. The essential oils of the samples were isolated by hydrodistilation, and methanolic extracts of the spices were also obtained. The changes in total phenolic content, 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferrus reducing antioxidant power (FRAP) and percent antioxidant activity (AA%) values (obtained by β-carotene-linoleic acid assay) were examined. The differences in antimicrobial activity was also evaluated by determining minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC) against Bacillus cereus, Escherichia coli, Staphylococcus aureus and Aspergillus niger. It was observed that gamma-irradiation increased the antioxidant and antimicrobial activities of the essential oils and the extracts of the spices. Total phenolic contents of black pepper essential oil and cumin extract were increased by irradiation, whereas it was decreased in rosemary essential oil. The DPPH radical scavenging activities of rosemary, black pepper and cumin essential oils as well as thyme extract followed an inclining pattern with increasing irradiation. Some increase due to irradiation in FRAP values of the extracts of all spices was noted. The AA% values of black pepper essential oil were increased with irradiation, where as a reduction with irradiation was observed cumin essential oil. It can be said that aerobic packaging enhanced the antioxidant activity. It was observed that irradiation increased antioxidant properties of aerobically packaged samples. It also noted that thyme essential oil and extract had greater antioxidant activity compared to others in most cases. Antimicrobial properties of spices, especially essential oils of thyme and cumin, were increased with irradiation. It was observed that A. niger was more susceptible to spice essential oils compared to B. cereus, E. coli and S. aureus. In addition, S. aureus was the most susceptible bacteria to the essential oils. Black pepper essential oil did not present any antibacterial effect against the bacteria examined. The antimicrobial effect of black pepper on was also low. Methanolic extract of thyme at 2,5-20 µg/mL concentration was sufficient to inhibit all the microorganisms. However, the extracts of rosemary, black pepper and cumin even at the highest possible concentration (20 µg/mL) did not show any antimicrobial effect on the microorganisms except B. cereus. In the last part of the study, the spice samples which were packaged under 100% N2 or air and irradiated at 6 kGy or 14 kGy were subjected to six months of storage under room temperature. The effects of irradiation and modified atmosphere packaging on microbial quality, CIELAB color values, sensory properties (color intensity, odor, overall liking), essential oil yield, and antioxidant (total phenolic content, DPPH, FRAP, β-carotene bleaching) and antimicrobial activity (MIC and MBC) of the spices during storage were evaluated. Similar to the findings obtained in the first part, gamma-irradiation provided the microbial quality of the spices before and after storage in both MAP and AP samples. It was observed that color values of the spices increased during storage compared to the beginning and lead to color loss. It was also noted that irradiation also caused color change, and this effect was greater at the beginning of the storage. The odor of cumin was higher in aerobically packaged samples at the beginning of the storage, which is believed to be a result of the increase of cuminaldehyde in aerobically packaged samples. There was no other differences in sensory color intensity, odor or overall liking values due to irradiation dose, package or storage. Generally, the essential oil yield, total phenolic content, DPPH radical scavenging activity and antimicrobial activity of spices followed a decreasing pattern during storage. However, FRAP and AA% values of the spices were higher at the end of the storage period compared to beginning. It was observed that the differences noted at the beginning of the storage due to packaging and irradiation were lost after storage. Overall, combination of irradiation with modified atmosphere packaging can be recommended to lower the loses in color and essential oil content of thyme, rosemary, black pepper and cumin. The results are promising that GC×GC can be used as tool to detect irradiation treatment of spices. Irradiation, modified atmosphere packaging and storage generally did not affect the sensory properties of the samples. Gamma-irradiation tended to increase the antioxidant activities of the essential oils and extracts of aerobically packaged spices, and the antimicrobial activities of modified atmosphere packaged the samples. Storage resulted in loss of essential oil yield, antioxidant and antimicrobial properties of samples in most of the cases, and the differences noted due to irradiation and packaging were lost during storage., Doktora, PhD