Tag Archives: refrigerated storage

1616–1628 J. Bazarnova, N. Barsukova, S. Eliseeva, V. Gnilitskiy and J. Shepiashvili
Shelf life extension of minimally processed vegetables using combinations of bacterial bioprotection and modified atmosphere packaging
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Shelf life extension of minimally processed vegetables using combinations of bacterial bioprotection and modified atmosphere packaging

J. Bazarnova, N. Barsukova, S. Eliseeva, V. Gnilitskiy and J. Shepiashvili

Peter the Great St. Petersburg Polytechnic University, Graduate School of Biotechnology and Food Science, Polytechnicheskaya, 29, RU195251 St. Petersburg, Russia

Abstract:

The objective of the work: to study the effect of combination of bacterial bioprotective cultures and modified atmosphere packaging for prolonging the refrigerated storage period of minimally processed vegetables. Sweet pepper, zucchini, eggplant, celery stalks were used for preparation of minimally processed vegetables. SafePro® bio-products from Chr. Hansen (Denmark) containing strains of Lactobacillus sakei, Pediococcus acidilactici, Lactobacillus сurvatus, Leuconostoc carnosum were used as bioconservatives. For packaging minimally processed vegetables, the bags made of flat multilayer PA/adhesive/PE films and composite PET/A1/PE film material were used. The bags were filled with gas mixtures including nitrogen and carbon dioxide. Storage of packaged minimally processed vegetables was carried out in a refrigerator at a temperature of 4 ± 2 °C for 16 days. The viability of cultures Lactobacillus sakei, Pediococcus acidilactici, Lactobacillus curvatus, Leuconostoc carnosum in modified atmosphere packaging was studied. It was revealed that the gas mixture of 60% nitrogen and 40% carbon dioxide and the culture of Lactobacillus sakei contribute to the preservation of the quality of fresh-cut sweet pepper, eggplant and zucchini, and Leuconostoc carnosum is the more effective for celery storing. In the process of refrigerated storage for 14 days, the solids content in the experimental samples increased 1.3–2.1 times, the loss of organic substances was 26–50%, depending on the type of vegetables. The developed technology for the refrigeration preservation of minimally processed vegetables using bio-products treatment and in modified atmosphere packaging made it possible to increase the shelf life of fresh-cut vegetables by 2 times.

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1738–1750 M. Kremenevskaya, V. Аret, E. Tambulatova, O. Sosnina, T. Shkotova, E. Kuprina, I. Makeeva, A. Manuylov, M. Kipchatova and A. Anikina
The usage of a binder system for frozen berries in the manufacture of confectionery
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The usage of a binder system for frozen berries in the manufacture of confectionery

M. Kremenevskaya¹, V. Аret¹, E. Tambulatova¹, O. Sosnina¹*, T. Shkotova¹, E. Kuprina¹, I. Makeeva², A. Manuylov¹, M. Kipchatova¹ and A. Anikina¹

¹ITMO University, Faculty of Food Biotechnologies and Engineering, 49 Kronverksky Pr., RU197101 St. Petersburg, Russia
²All-Russian Research Institute of Dairy Industry, Lyusinovskaya Str. 35 Bldg. 7, RU115093 Moscow, Russia
*Correspondence: sosnina.olga.itmo@yandex.ru

Abstract:

The aim of the research was to create binding systems for confectionery using gelling agents. The possibility of using partially hydrolyzed liquid egg white (egg hydrolyzate) in the binding system of gelling agents (egg hydrolyzate – agar (EG-A), egg hydrolyzate – starch (EG-S)) was determined to obtain the required mechanical characteristics when creating coatings, ornaments or fillers in confectionery with whole berries or pieces of fruit. In this regard, a technology has been developed for the hydrolysis of liquid egg white in the presence of an acidic reagent. The best rheological characteristics of the gelling agent from egg white were obtained under the following hydrolysis conditions: egg white : 1% HCl ratio = 1:2, process temperature – 66°C, duration – 40 minutes, the pH of the egg hydrolyzate was 6.53, the amount of dry solids was 11.78%. The newly created systems with agar (E406, Germany), chemically modified food starch (E1442, Germany) and hydrolyzed egg white (egg hydrolyzate) allow to adjust the properties of the coating for quick-frozen berries used in semi-finished confectionaries or cakes. It is established that the coating for quick-frozen berries, which includes a system consisting of 1% E406 and 0.5% egg hydrolyzate, should be carried out in 2 stages. In the first stage, a 10-minute exposure of the coating, which has a tensile strength of 580 g cm-2, allows to create a strong capsule around the berry, which prevents the processes of destruction from proceeding. The second stage is necessary to obtain a uniform surface coating of the semi-finished mix from the berries. In this case, the tensile strength of the coating should be 480 g cm-2. The system created from the E1442 and egg hydrolyzate gelling agents was also used in 2 stages when making cakes, which were subsequently baked at 180 °C. The content of the binding system in the coating applied to the test substrate was 6.9–7.7%, the effective viscosity of the coating was 120–180 Pa s. The content of the binding system in the coating of the surface of the berries in the second stage was 5.2–6.3% with effective viscosity values of 50–90 Pa s. Semi-finished berry products and ready-made baked cakes, produced with developed binding systems, can be stored at -8 °C for 10 to 12 days. After refrigerated storage, the separated moisture was not observed in the test samples. The absence of the phenomenon of syneresis with the indicated proportions of the introduction of gelling agents in coating systems has been established.

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815-826 M. Musto and M. L. Satriano
Fruit responses to postharvest heat treatment time: characterisation of heat-treated strawberry (Fragaria x ananassa) cv. ‘Candonga’ fruits
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Fruit responses to postharvest heat treatment time: characterisation of heat-treated strawberry (Fragaria x ananassa) cv. ‘Candonga’ fruits

M. Musto¹ and M. L. Satriano²

¹Metapontum Agrobios S.r.l., s.s. 106 Jonica Km 448.2, 75010 Metaponto (MT), Italy;
e-mail: mauro.musto@gmail.com
²Freelance researcher

Abstract:

Strawberries cv. ‘Candonga’ were heat-treated in an air oven (45°C) for 0.2 and 4 h,
and then stored at 0°C for 2 days. One-way ANOVA revealed significant differences in terms of
physical and chemical quality properties due to heat treatment time (P=0.000). In particular, as
treatment time increased, strawberries showed a significant decrease of weight, firmness,
redness (a*), yellowness (b*) and colour saturation (chroma). Additionally, the fruits were
darker (lower L* value) after 2 h of treatment and lighter after 4 h (higher L* value). Among
chemical quality properties, ph and soluble solids content (SSC) increased during treatments,
whereas vitamin C content (TAA) decreased. After 4 h of treatment, total anthocyanins and total
soluble phenolics (TSP) significantly decreased and increased, respectively. Principal
component analysis (PCA) was executed on the correlation matrix of significant variables. Two
principal components were extracted, explaining the 73.38% of the data variance. PC1 (60.15%
variance) was associated with most of the physical and chemical variables, whereas PC2
(13.23% variance) was associated with fruit lightness. PCA was found to be of value in
obtaining a visual representation of fruit samples based on heat treatment time.

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