Deterioration due to delayed icing and its impacts on the nutritional quality of Malabar travally (Carangoides malabaricus)

Effect of delayed icing of the fish Carangoides malabaricus was assessed using chemical and microbial methods to determine the impacts on the nutritional quality and sensory changes. The shelf life of the fishes iced immediately after harvest had a shelf life of 18 days, whereas the delay of icing for 4, 6, 8 and 10 h shortened the shelf life to 14, 10, 6 and 3 days respectively. The spoilage indicators, such as trimethylamine nitrogen, Total volatile basic nitrogen, free fatty acids, peroxide value, thiobarbituric acid and pH values, significantly increased (P < 0.05) during the storage period of fishes with delayed icing. The total bacterial count also increased during the storage period and due to quality deterioration, the protein and lipid contents were found significantly low (P < 0.05). This study showed that chemical and microbial changes of the sample are well correlated with nutritional and sensory qualities so that immediate icing is important for maintaining the quality and shelf life of C. malabaricus.     

Studies on saffron (Crocus sativus L.) from Tuscan Maremma (Italy): effects of geographical origin,cultivation environment and drying method on volatile emission

Saffron (Crocus sativus L.) is a spice used in the food industry in an ever increasing, partly due to consumer preference for natural products . Crocus sativus stigmas are converted into saffron spice by a dehydration treatment. The postharvest treatment of the stigmas, particularly the drying process, is critical to the quality of saffron as measured by the level of secondary metabolites. The aim of this project was to study the volatiles compounds in saffron that came from three different sites of the Maremma Grossetana (Grancia, Pari and Alberese) (Tuscan). The corms were grown both in the place of origin and in the province of Pisa. Fifteen compounds were detected, accounting from 92.3% to 97.8% of the total volatiles. The main characteristic volatile compounds of the dried stigmas saffron were safranal, isophorone, 4‐keto isophorone, γ‐pyronene, dihydrooxophorone. Differences were found in the composition of volatile compounds both based on the place of cultivation and in a function of time of dehydration.     

Shelf life and quality of probiotic yogurt produced with Lactobacillus acidophilus and Gobdin

This study evaluated the effect of dry white mulberry and walnut paste (Gobdin, a traditional Turkish food) in probiotic yogurt on the survival of Lactobacillus acidophilus and yogurt properties. Six different yogurts were produced with 0%, 5% and 10% Gobdin using Lactobacillus bulgaricus + Streptococcus thermophilus and with 0%, 5% and 10% Gobdin using L. bulgaricus + S. thermophilus + L. acidophilus. The physical, chemical, microbiological and sensorial properties of the yogurts were evaluated based on storage at 4 ± 1 °C. Probiotic shelf life and the most suitable combinations were determined. The highest L. acidophilus count (8.65 log cfu g^?1) was found in the 5% Gobdin‐supplemented yogurt on the 7th day of storage, while the lowest count (8.11 log cfu g^?1) was found in the probiotic control yogurt on the 21st day. Although the L. acidophilus counts in the probiotic yogurts declined during storage, all values found throughout the 21‐day storage period were >8 log cfu g^?1. This is above the level necessary to provide the desired therapeutic effect in probiotic products (10⁶–10⁷ cfu g^?1). The highest overall acceptability score was obtained on the first day from the yogurt with 5% Gobdin. However, all yogurt samples had general acceptability scores between 7 and 8 points from a 9‐point maximum. Thus, this study determined that a new functional yogurt can be produced using L. acidophilus with 5% Gobdin.     

Changes during storage of dried Moringa oleifera leaves prepared by heat pump‐assisted dehumidified air drying

Moringa oleifera leaves contain phytochemicals that are retained during heat pump‐assisted dehumidified air drying. Changes in phytochemicals, antioxidant capacity and colour were evaluated at 15–35 °C, during storage of dried leaves in polypropylene (PP) or high barrier (PET/Al/PE) packaging for up to 6 months. The a_w of samples in PP increased from 0.373 to 0.669. Decreases in total phenolics were greatest at 35 °C in PP (48%) and least at 15 °C in PET/Al/PE (19%). There were few significant changes in DPPH inhibition after 2 months storage. There was little change in kaempferol and some increase in quercetin. During storage, samples became less green, suggesting breakdown in chlorophyll had occurred. The degradation of flavonoids followed first‐order kinetics. The half‐life for total flavonoids ranged from 2.13 to 1.47 months for samples stored in PP and from 2.59 to 1.83 months for samples stored in PET/Al/PE.     

Antioxidative and antimicrobial activities of shrimp chitosan on gilthead sea bream (Sparus aurata) during refrigerated storage

This study aims to determine the effects of chitosan obtained from Metapenaeus stebbingi shells on the shelf life of refrigerated gilthead sea bream. It was determined that 1% chitosan‐coated samples had the lowest thiobarbituric acid (TBA) (3.05 mg malondialdehyde (MDA) kg^?1) and free fatty acids (FFA) value (2.79% oleic acid), while the control group had the highest TBA (5.08 mg MDA kg^?1) and FFA value (6.13% oleic acid) on the 27th day of storage. In the last day of storage, TVB‐N was found higher in control group (25.62 mg 100 g^?1) than chitosan‐coated samples (14.57 mg 100 g^?1). Total viable count value of the control group exceeded maximum permissible limit on the 27th day of storage. However, it was lower than 7.0 log CFU/g in chitosan‐coated samples during the refrigerated storage. As a result of this study, it was determined that shelf life of refrigerated gilthead sea bream can be increased up to 27 days with chitosan.     

Microbial inactivation and quality improvement of tomatoes treated by package film with allyl isothiocyanate vapour

In‐package sanitisation was developed using polylactic acid (PLA) films with allyl isothiocyanate (AIT) vapour. Tomatoes were artificially inoculated with Escherichia coli, Geotrichum candidum and Fusarium oxysporum and stored in clamshell boxes with the film fixed to the underside of the lid. The changes in bacterial and fungal populations and the quality of tomatoes during storage at 4 and 10 °C were evaluated. The results revealed that the film treatment (4 × 8 cm² film in 1 L box) reduced the populations of inoculated bacteria and fungi on tomatoes by 2–3 log CFU g^?1, and then significantly (P < 0.05) inhibited their growth during the 21‐day storage period at both temperatures. Tomatoes subject to film treatment had fewer changes in quality (colour, firmness, contents of total soluble solid, titratable acids and vitamin C) than the control samples during storage. The antimicrobial PLA film can be used for in‐package sanitisation to extend the shelf‐life of packaged tomatoes or similar perishable vegetables.     

Effect of saffron addition on the microbiological,physicochemical, antioxidant and sensory characteristics of yoghurt

The impact of added saffron on the characteristics of yoghurt was evaluated during storage. The fat content was lower in the saffron yoghurt. All colour variables were significantly affected by saffron and storage. From the 15th day of storage, bacterial numbers in the saffron yoghurt were higher than those of the control yoghurt. Sensory analysis data suggested that colour, odour and texture impacted consistently on the overall acceptability of the saffron yoghurt. Saffron addition significantly increased polyphenol content and antioxidant activity, providing evidence that the enrichment of natural yoghurt with saffron yields an innovative fermented product useful for supplementing antioxidant dietary intake.     

A comparative study on phenolic profile,vitamin C content and antioxidant activity of Italian honeys of different botanical origin

The aim of our study was to identify and quantify the phenolic acids, flavonoids and vitamin C and to evaluate the antioxidant activity in ninety Italian honeys of different botanical origins (chestnut, sulla, eucalyptus, citrus and multifloral). The results showed that total phenolic and flavonoid contents varied from 11.08 to 14.26 mg GAE per 100 g honey and from 5.82 to 12.52 mg QE per 100 g honey, respectively. HPLC–UV analysis showed a similar but quantitatively different phenolic profile of the studied honeys. Vitamin C is present in all samples. Multifloral honey showed the highest amount of the detected total phenolic compounds and the highest vitamin C content. The DPPH value varied from 55.06 to 75.37%. Among the unifloral honeys, chestnut honey presented the highest levels of phenolic acids, flavonoids and vitamin C, which are closely associated with its high antioxidant activity. The results show that honey contains high amount of biologically active compounds, which play an important role in defining the nutraceutical quality of the product, and that the distribution of these compounds is influenced by the botanical origin.     

Genotypic effects on the phytochemical quality of seeds and sprouts from commercial broccoli cultivars

Determining ontogenic diversity in vegetables, in general or Brassicas in particular, regarding the bioactive content, is an interesting task since the most promising Brassicaceae foods could have the highest nutritional and health-promoting properties. Therefore, vitamin C, phenolic compounds, glucosinolate content, and total antioxidant capacity were evaluated in commercial cultivars of broccoli (Brassica oleracea var. italica; cv. Nubia, cv. Marathon and cv. Viola) seeds and during the sprouting period. Vitamin C was not detected in dormant seeds and its content increased with the germination, reaching values ranging from 53 (cv. Nubia) to 64 (cv. Marathon) mg/100 g FW, at the end of the monitored period (14days). The total glucosinolate content in seeds and 3-day-old sprouts was higher in cv. Marathon (1005 and 556 mg/100 g FW, respectively), however cv. Viola sprouts registered the highest glucosinolate content 7 and 14 days after sowing (235 and 208 mg/100 g FW, respectively). Aliphatic glucosinolates were more affected by genetic factors than the indolic glucosinolates, being glucoraphanin the predominant glucosinolate in cv. Nubia and cv. Marathon, whereas glucoiberin was the major glucosinolate in cv. Viola. The flavonoid and total phenolic content was significantly higher in cv. Viola. Also, seeds of this cultivar showed the highest antioxidant capacity (2.7 mg Trolox/g FW).     

Effects of culture substrates on taste component content and taste quality of Lentinula edodes

In this research, the effects of culture substrates on taste component content of Lentinula edodes were studied, and the resulting taste quality of L. edodes was evaluated. The results revealed that single‐carbon and single‐nitrogen sources were beneficial to production of soluble sugars and polyols, organic acids and sweet amino acids, whereas a single‐carbon source was beneficial to essential amino acid production, and a mixed‐carbon source was beneficial to umami 5′‐nucleotides and high mushroom production yield. High C/N values were beneficial to trehalose, arabitol, malic acid, and succinic acid production, while low C/N values were beneficial to mannitol and citric acid production. L. edodes fruiting bodies, harvested from a culture substrate containing single carbon, high proportion of cereal bran, had a more palatable taste quality, while a substrate containing bagasse and low C/N values was not suitable for L. edodes cultivation due to unfavourable taste quality. These results provide cultivation information how to obtain fruiting bodies L. edodes with more taste components.     

Freshness retention of minimally processed melon using different packages and multilayered edible coating containing microencapsulated essential oil

This study evaluated the effectiveness of packaging using a microencapsulated β‐cyclodextrin and trans‐cinnamaldehyde complex incorporated into a base chitosan matrix on the shelf life of fresh‐cut melon (Cucumis melo L. var. Reticulatus Naud) group Inodorus that were coated with a multilayered coating system using a polypropylene tray (Ziploc^®) with (i) Ziploc^® lid, (ii) Saran^® wrap and (iii) plain cheesecloth and stored at 4 °C for 15 days. The multilayered antimicrobial coating improved the shelf life of fresh‐cut melon (up to 15 days), compared with the controls (7 days). Coated samples were firmer, maintained colour and total carotenoids content and showed less weight loss than the controls (P < 0.05). Among the packaging treatments, the Ziploc^® lid was the most effective in maintaining shelf life. This study demonstrates the application of a new generation of edible coating using natural antimicrobial agents by means of the layer‐by‐layer assembly.     

Effect of consecutive steeping on antioxidant potential of green,oolong and black tea

After water, tea is considered to be one of the most consumed drinks worldwide. To get the maximum benefit from the whole‐leaf teas, the manufacturers provide instruction that these teas can be steeped 2–3 times over 6–8 h. In this study, the effect of consecutive steeping on radical‐scavenging ability of whole leaf green tea (unfermented), oolong tea (partially fermented) and black tea (fully fermented) was determined. Green tea showed the highest level of antioxidant activity, total phenolic and flavonoid content followed by oolong tea and black tea irrespective of the number of steeping done. The result also demonstrated that re‐steeping reduced the antioxidant potential of teas. Moreover, it was revealed that green tea is the best candidate for re‐steeping followed by oolong and then black tea.     

The effect of enzymatic hydrolysis on the biological properties of Oenothera biennis,Borago officinalis and Nigella sativa seedcake by‐products from oil pressing

The biological properties of ethanolic (50%, v/v) extracts from Oenothera biennis, Borago officinalis, Nigella sativa seedcake before and after enzymatic hydrolysis by alpha‐amylase (EC 3.2.1.1) from Aspergillus oryzae, beta‐glucosidase (EC 3.2.1.21) and beta‐glucanase (EC 3.2.1.6) from Aspergillus niger combinations in a ratio of 1:1:1 were investigated. Total phenolic, flavonoid and reducing sugar content for O. biennis extract after enzymatic hydrolysis was, respectively, 0.5, 1.5 and 2 times higher in comparison with nonhydrolysed extract. Iron‐chelating and radical‐scavenging activity of O. biennis seedcake extract after hydrolysis (IC₅₀ = 0.076 mg mL^?1 and IC₅₀ = 0.050 mg mL^?1) was at a similar level as that nonhydrolyeed (IC₅₀ = 0.070 mg mL^?1 and IC₅₀ = 0.065 mg mL^?1). The antioxidant activity was two times higher after hydrolysis than before enzymatic hydrolysis of O. biennis seedcake extract. Also strong elastase inhibition activity has been shown to O. biennis seedcake extract before (IC₅₀ = 0.095 mg mL^?1) and after enzymatic hydrolysis (IC₅₀ = 0.07 mg mL^?1), respectively. Oenothera biennis and B. officinalis seedcake extracts before and after hydrolysis have stronger antibacterial activity against Pseudomonas aeruginosa strain in comparison with N. sativa seedcake.     

水分含量对软烤扇贝品质变化和菌相组成的影响

以感官、化学和微生物为指标,研究了水分含量为43％、46％、49％和52％的软烤扇贝30℃贮藏过程中的品质变化和货架期,并对菌相组成及其变化进行了分析.结果表明,随着水分含量的升高,样品货架期变短;相同时间内菌落总数上升明显,各组差异较大,样品菌相组成逐渐由单一变得复杂;水分含量对样品pH变化影响不大,各组之间差异不显著.结果表明生产过程中应降低产品水分含量以获得良好的货架期和口感.本文为温和加工扇贝的产品品质和贮藏安全性提供了理论依据.     

The effect of natural and liquid smokes on the benzo[a] pyrene content and quality parameters of Circassian cheese

The objective of this study was to determine the effects of natural smoke and liquid smoke application methods on quality characteristics of smoked Circassian cheese. The microbial counts of liquid smoked cheeses were found to be higher than naturally smoked cheeses. It can be concluded that although natural smoke inhibited the growth of micro‐organisms more than liquid smoke application, benzo[a]pyrene, an indicator component for polycyclic aromatic hydrocarbons (PAH), was detected on the outer surface of naturally smoked cheeses. Therefore, liquid smoking could be used as an alternative method for smoked Circassian cheese production.     

Composition of eggplant cultivars of the Occidental type and implications for the improvement of nutritional and functional quality

We have investigated the diversity for composition in seven eggplant (Solanum melongena) cultivars of the Occidental type. The results show that, with the exception of moisture content and pH, there is a wide diversity for all the analysed traits. Protein content was variable, but generally low. The content in available carbohydrates ranged between 2.99 and 4.19 mg 100 g^?1, and the main soluble sugars were glucose and fructose. The fibre content was the most variable trait. In all cases, the dehydroascorbic acid content was higher than the ascorbic acid content. Total phenolics content was on average thirty‐nine‐fold higher than vitamin C content. Multivariate analysis showed that accessions from the black and striped groups presented a similar composition profile, while the white and pickling fruits were very distinct. The pickling eggplant H11 is identified as the best source for improving the nutritional and functional properties of Occidental eggplants.     

Modelling growth of Lactobacillus plantarum and shelf life of vacuum‐packaged cooked chopped pork at different temperatures

Lactobacillus plantarum growth in a vacuum‐packaged cooked meat product under different storage temperatures (4, 10 and 16 °C) and the relation between the microorganism growth and sensory quality were investigated. The Gompertz model was fitted to experimental counts of L. plantarum showing a good fitting to growth curves at different temperatures. A root‐square secondary model and linear model were satisfactorily fitted to estimated growth rates () and lag times (), respectively. The sensory attributes (colour, flavour, taste, appearance) were also evaluated due to their importance to the global quality (Q). The sensory deterioration was detected several days after L. plantarum reached the stationary phase, that is, 59, 45 and 25 days for 4, 10 and 16 °C, respectively. According to results, sensory deterioration was related to time when microorganism reached late stationary phase, phenomenon known as ‘delayed change’.