scholarly journals Comparison of different thawing methods effect on the calorimetric and rheological properties of frozen liquid egg yolk

Author(s):  
Karina Ilona Hidas ◽  
Csaba Németh ◽  
Anna Visy ◽  
Adrienn Tóth ◽  
László Ferenc Friedrich ◽  
...  

AbstractEggs are commonly used in the food industry because of their excellent nutrient value and also for their coagulating, foaming, emulsifying, colouring and flavouring properties. Manufacturers substitute shell eggs with processed egg products, such as liquid whole egg, liquid egg yolk or albumin. They have a shelf life of a few weeks, but freezing can increase it to 1 year. However, freezing causes gelation in case of egg yolk. This process is highly dependent on the conditions of freezing and thawing.In our study, raw liquid egg yolk was frozen and stored for 14 days at −18 °C. On days 1, 7 and 14 samples were thawed by two different methods. Denaturation temperature and enthalpy were investigated by differential scanning calorimetry. Besides, rheological properties were examined at 20 °C, Herschel–Bulkley model was fitted to flow curves of the examined samples. The dry matter content was also recorded during the experiment. Two-way ANOVA was used to analyse data.The results of the study showed that method of thawing had no significant effect on calorimetric and rheological properties and dry matter content. In contrast, freezing and frozen storage had a significant effect on denaturation enthalpy and rheological properties.

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidas Karina Ilona ◽  
Ildikó Csilla Nyulas-Zeke ◽  
László Friedrich ◽  
Anna Visy ◽  
Judit Csonka ◽  
...  

Eggs are widely utilized because of their high nutrient value, coagulating, foaming, emulsifying and sometimes even colouring or flavouring facilities in food manufacturing. Production of processed egg products shows an increasing trend. Frozen products belong to first processing, their shelf life can increase up to 1 year. By freezing, a large reduction in microbial loss can be achieved. But different undesirable processes can occur. The effect of freezing on animal cells is highly dependent on freezing parameters. It has a different effect on egg subtituents. Egg yolk undergoes a gelation process while proteins can denaturate. In our study pasteurized liquid egg products (liquid egg white, liquid egg yolk and liquid whole egg) were frozen by dripping into liquid nitrogen. After that, a 14-day frozen storage experiment was carried out at -18°C. Before freezing and on the 1th, 7th and 14th days of storage experiment pH, dry matter content, colour and calorimetric properties (denaturation temperatures and enthalpy of denaturation) with differential scanning calorimetry were tested. For statistical analysis, one-way ANOVA (α = 0.05) was employed. In our experiment, we found no significant change in calorimetric properties of liquid egg white after freezing, but significant decreasing of enthalpy and denaturation temperatures of liquid egg yolk and liquid whole egg was identified. In contrast, frozen storage had a decreasing effect in all these products. Freezing caused a clearly visible colour change in LEW, a visible change in colour of LWE and a very clearly visible change in colour of LEY. In case of LEW and LEY changes increased to clearly visible 14 days. In conclusion, our results show that frozen storage had a greater effect on liquid egg products properties than freezing in liquid nitrogen.


2020 ◽  
Vol 12 (24) ◽  
pp. 10389
Author(s):  
Karina Ilona Hidas ◽  
Anna Visy ◽  
Judit Csonka ◽  
Ildikó Csilla Nyulas-Zeke ◽  
László Friedrich ◽  
...  

In the last few decades, convenience has become one of the most important factors for consumers. Therefore, food products that take a short time to prepare are gaining in popularity. The aim of this study was to develop a gluten-free egg-pie product which is quick-frozen in pre-baked form and remains usable for a long time. Besides, it satisfies various consumer needs while remaining sustainable by not having a great impact on the environment. A dough containing rice, millet, and buckwheat flour was developed. The fillings also appeared in unflavored and flavored form (spinach onion, cheese) with and without increased egg white content. Acceptance of the product was measured by sensory test. Texture and dry matter content measurement, triangular test, and color measurement were performed to track changes through six months of frozen storage. The stored pies’ hardness declined for three months, then doubled the original value at the end of the frozen storage. The stored pies hardness declined for three months (from 10.76 ± 1.78 and 11.22 ± 1.47 N to 8.52 ± 1.74 and 9.91 ± 1.16 N), then doubled the original value at the end of the frozen storage (21.69 ± 2.55 and 19.62 ± 1.67 N). The dry matter content showed increasing tendency. Results of the triangular tests showed that the stored flavored pies were less distinguishable from freshly baked ones than the unflavored egg-pies. Color measurement showed that the fillings of the pies were darkening during the frozen storage. Consumer liking test showed values between 6.52 ± 1.76 and 7.56 ± 1.2 on a 9-point hedonic scale. Color measurement showed that the fillings of the pies were darkening during the frozen storage, and the lightness values decreased from 90.17 ± 0.06 and 90.53 ± 0.11 to 81.43 ± 0.41 and 83.22 ± 0.87 in six months. Results generated in this study suggest that consumers’ acceptance was high, though results of penalty analysis showed that more flavorings would increase the overall acceptability.


1970 ◽  
Vol 39 (1-2) ◽  
pp. 163-169
Author(s):  
MM Rahman ◽  
MJ Khan ◽  
SD Chowdhury ◽  
MA Akbar

An experiment was conducted to investigate the effect of feed supplementation on chemical composition of Jinding duck’s egg. A total of 180 physically sound eggs were randomly collected in each time at 50% and 75% level of egg production of the ducks. Significant difference was observed for dry matter content of egg albumen of ducks fed on different diets at 50% level of egg production (P<0.01) but no significant difference was recorded for dry matter content of egg yolk at 50% level of egg production (P>0.05). The CP contents of egg albumen and egg yolk differed significantly (P<0.01) at 50% level of egg production but the difference was not significant (P>0.05) for CP content of egg yolk at 75% level of production. There were significant differences (P<0.01) on EE and TA contents of egg albumen and egg yolk at all levels of production. The results of the study demonstrated that the dry matter, as well as crude protein, ether extract and total ash content of eggs on dietary treatment T1(Scavenging + standard ration) was highest compared to the eggs on other treatment groups (T0, T2, T3, T4 and T5). Key words: Feed supplementation; Chemical composition; Jinding duck; Scavenging; Coastal areas. DOI: http://dx.doi.org/10.3329/bjas.v39i1-2.9690 Bang. J. Anim. Sci. 2010, 39(1&2): 163-169


2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.


2020 ◽  
pp. 16-19
Author(s):  
Е.В. Янченко

Цель исследований – дать оценку сохраняемости и болезнеустойчивости современных сортов и гибридов моркови столовой и определить корреляционные зависимости влияния биохимических показателей качества на сохраняемость и степень поражения моркови столовой различными видами болезней в процессе хранения. Исследования проводились в 2011–2016 годах во ВНИИО – филиале ФГБНУ ФНЦО по общепринятым методикам. В биохимической лаборатории отдела земледелия и агрохимии содержание сухого вещества определяли высушиванием до абсолютно сухого веса, общего сахара – по Бертрану, аскорбиновой кислоты – по Мурри, нитраты – ионоселективным методом. При характеристике моркови столовой важнейший показатель, определяющий его качество – количество сухого вещества и сахаров. В процессе хранения были выявлены следующие болезни моркови: серая гниль (Botrytis cinerea Pers. ex Fr.), белая гниль (Sclerotinia sclerotiorum (Lib.)), белая парша (Rhizoctonia carotae Rad.), альтернариоз (Alternaria radicina M., Dr. et E.). В большей степени сортообразцы моркови столовой поражались серой гнилью. Лучшими по сохраняемости сортообразцами были Корсар (94,6%), F1Берлин (94,5%), Берликум Роял (94,1%) и F1 Звезда (94%). Сохраняемость у зарубежных сортов и гибридов моркови столовой была немного выше, чем у отечественных (на 0,4%) как за счет меньшей величины убыли массы (6,3% против 6,4%), так и потерь от болезней (1,6% против 1,9%). Сохраняемость корнеплодов моркови находится в прямой корреляционной зависимости от содержания сухого вещества (r=+0,41), каротиноидов (r=+0,39), моносахаров (r­=+0,30) и суммы сахаров (r=+0,27). Проявление серой гнили находится в обратной корреляционной связи с содержанием сухого вещества и каротиноидов (r=-0,37 и r=-0,35 соответственно), белой парши – в прямой корреляции с содержанием сухого вещества , моносахаров и дисахаров (r= +0,21; r= +0,39; r= -0,41 соответственно), белой гнили в обратной корреляционной связи с содержанием сухого вещества, моносахаров и дисахаров. The purpose of the research is to assess the persistence and disease resistance of modern varieties and hybrids of carrots and to determine the correlation between the influence of biochemical quality indicators on the persistence and degree of damage to carrots by various types of diseases during storage. The research was conducted in 2011–2016 at ARRIVG – branch of FSBSI FSVC, according to generally accepted methods. In the biochemical laboratory of the Department of Agriculture and Agrochemistry, the dry matter content was determined by drying to absolutely dry weight, total sugar – by Bertran, ascorbic acid – by Murri, nitrates – by the ion-selective method. When describing carrots, the most important indicator that determines its quality is the amount of dry matter and sugars. During storage, the following diseases of carrots were detected: gray rot (Botrytis cinerea Pers. ex Fr.), white rot (Sclerotinia sclerotiorum (Lib.), white scab (Rhizoctonia carotae Rad.), alternariasis (Alternaria radicina M., Dr. et E.). To a greater extent, varieties of table carrots were affected by gray rot. The best preserved varieties were Corsar (94.6%), F1 Berlin (94.5%), Berlicum Royal (94.1%) and F1 Zvezda (94%). The persistence of foreign varieties and hybrids of table carrots was slightly higher than that of domestic ones by 0.4%. both due to a smaller amount of weight loss (6.3% vs. 6.4%) and losses from diseases (1.6% vs. 1.9%). The persistence of carrot root crops is directly correlated with the content of dry matter (r=+0.41), carotenoids (r=+0.39), monosaccharides (r=+0.30) and the amount of sugars (r=+0.27). The manifestation of gray rot is in inverse correlation with the content of dry matter and carotenoids (r=-0.37 and r=-0.35, respectively), white scab is in direct correlation with the content of dry matter (r= +0.21; r= +0.39; r= –0.41, respectively), white rot is in inverse correlation with the content of dry matter, monosaccharides and disaccharides.


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