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The emulsification potential of milk fat globule membrane (MFGM) material obtained from buttermilk whey was investigated. A microfiltration technique was applied to recover MFGM material from the whey, a side-stream of the cheese-making process from the buttermilk. During the preparation of O/W emulsions, a constant ratio of protein and oil was maintained, and homogenised at 0/2, 3/2, 9/2, and 15/2 MPa pressures using a two-step homogeniser. Emulsions prepared with buttermilk powder (BMP) and microfiltrated buttermilk whey (MFBMW) showed similar microstructure and rheological properties. The particle distribution and mean diameter (D3,2) were similar for both materials. However, no cream separation was observed for emulsion prepared with MFBMW during 8-day storage. Despite the differences in the composition, MFBMW showed good creaming stability, and similar emulsifying properties to BMP. These results demonstrated the future perspective of whey valorisation in a high food value dairy application.

Fresh-cut lettuce is a very well-known salad for today's routines because it obliges minimal preparation to minimize the loss of health beneficial vitamins, minerals, antioxidants and other phytochemicals. It is a prodigious challenge to serve its consumers fresh. Quality of freshly processed lettuce under high CO2 modified atmosphere packaging (MAP) has been investigated as a realistic alternative technique for its preservation. Storage under high CO2 atmospheric treatments exhibited a significant impact in microbial development, electrolyte leakage, volatile metabolites and sensory quality of fresh-cut iceberg lettuce. This storage condition (MAP 1: 5 kPa O2 and 20 kPa CO2 balanced by N2 at 7 °C for 6 days) inhibited the growth of mesophilic bacteria and yeasts; delayed the enzymatic browning (cut-edges and intact surface) of fresh-cut iceberg lettuce and overall visual quality was also in acceptance limit. The development of off-odors was perceived in high CO2 MAP as a consequence of volatiles (ethanol and acetaldehyde) accumulation which was persisted at an inexcusable level during 6 days of storage periods.

Recently, consumers have tended to functional foods with more natural antioxidants, dietary fibers, minerals, vitamins, natural colorants and free of synthetic additives, etc. and tomato juice ice-cream will greatly contribute to this feature. This study determines the effect of tomato juice concentrations on the physico-chemical, functional and sensory properties of tomato juice ice cream. pH, texture, viscosity, melting rate and overrun were used to analyze the physico-chemical and functional properties of ice cream. The sensory parameters were colour, flavor, hardness, taste, mouthfeel, iciness and overall acceptability. Ice cream with 2.17 % (S2), 6.25 % (S3), 10 % (S4) tomato juice were incorporated to prepare tomato juice ice cream and the properties were evaluated along with the control ice cream (S1= 0 % tomato juice). The pH and overrun of ice cream samples was decreasing with the increasing percentage of tomato juice. But, the firmness and viscosity was increasing with the increasing amount of tomato juice. pH value of the tomato juice ice creams was lower indicating the higher acidity. The highest firmness (3.63±0.02) and viscosity (355±3.00) was exhibited by S4 sample. It was observed that 10 % tomato juice ice cream showed higher melting rate and lowest was found for S1. The sensory analysis showed that the samples were not significantly different at 5 % level of significance except S3 for colour and overall acceptability. It indicated that the consumer acceptance for S3 was slightly more than the S1, S2 and S4 sample. At last, it can be recommended that tomato can be incorporated into ice cream for large scale production of ice-cream. Keywords: ice cream, Lycopersicon esculentum Mill., physico-chemical properties, sensory evaluation, texturometer Cite this Article Md. Anowar Kabir , Md. Bodrul Islam Talukder , Laizu Islam, Sabina Yasmin, Md. Sultan Mahomud, Joysree Roy. Evaluation of physiochemical, functional and sensory properties of ice-cream incorporated with tomato juice. Research & Reviews: Journal of Dairy Science & Technology . 2020; 9(1): 1–9p.

This study investigated the effect of micellar κ-casein dissociation, caused by cross-linking agent glutaraldehyde, on the formation of soluble protein complexes and the texture of resulting gels. Reconstituted skim milk containing different levels of added glutaraldehyde (SM-GTA) and skim milk without glutaraldehyde (SM) were processed with or without heating, and the structural properties of the prepared acid gel were studied. Acid gel prepared from heated SM (without GTA) had significantly higher firmness (1.40 ± 0.02 N) and water holding capacity (79.0 ± 3.0%) compared to that made from heated SM treated with 0.1, 0.3, 0.5 mmol/L GTA, respectively. Higher storage modulus (G′) and denser microstructure were observed in acid gel prepared from heated SM than those made from heated SM-GTA. Electrophoretic analysis demonstrated that κ-casein levels in the soluble protein complexes of SM was 9.60 ± 0.2 (%) which was decreased to 0.06 ± 0.01 (%) in SM treated with 0.5 mmol/L GTA. This was attributed to GTA decreasing micellar κ-casein dissociation and, therefore, reducing the formation of soluble protein complexes. This reduction in soluble protein complexes in SM-GTA resulted in weaker acid gels compared with those prepared from SM without GTA.

The effects of whey protein concentrate (WPC) on the formation of soluble protein complexes and yoghurt texture were evaluated. Skim milk (SM) and skim milk enriched with 1% WPC (SM + 1%WPC) or 2% WPC (SM + 2%WPC) were left unheated or heated and then made into yoghurt gels. Yoghurt prepared from heated SM + 2%WPC had significantly higher storage modulus, water holding capacity and firmness values and a denser microstructure than those prepared only from skim milk. Electrophoretic analysis of the milk showed that the level of β-lactoglobulin and κ-casein in the serum phase increased with increasing WPC concentration, indicating that the content of disulfide-linked β-lactoglobulin and κ-casein was higher in SM + 2%WPC than in SM, suggesting that more soluble protein complexes had been formed. Consequently, yoghurt prepared from heated SM enriched with WPC may have more bonds and more protein complexes in the protein network than yoghurt prepared only from SM, thus resulting in firmer gels. Practical applications Yoghurt, one of the most popular fermented milk products, is of high economic importance to the dairy industry worldwide. In particular, high-protein yoghurt, such as Greek-style or set-type yoghurt, has been driving its ongoing popularity over recent years. In current industrial production of high-protein yoghurt, protein fortification and heat treatment of milk are two of the most important processing parameters affecting yoghurt texture. Whey protein concentrate has been added to milk to reduce whey separation and to increase the firmness of the yoghurt. From a technological point of view, the interaction of the denatured whey proteins with casein micelles or with κ-casein in the serum phases is regarded as responsible for obtaining a good yoghurt structure. The present research has shown that it is possible to produce yoghurt with a range of textural properties by precisely controlling the rate of whey protein fortification during its manufacture. Therefore, this study provides a better understanding of the effect of WPC fortification and aims to extend this insight for the production of good-quality yoghurt.

Properties of yoghurt extremely depend on the application of heat treatment to milk prior to manufacture. After heating the milk, denatured whey protein and casein makes complexes which dramatically improve the yoghurt texture such as firmness and water holding capacity etc. The formation of complexes, micelle bound or soluble whey protein/k-casein complexes, and their localization between casein micelles and serum depends on the physical properties (heat treatment, pH, compositions) of milk. We review the formation of these complexes and their effect on the physical, rheological and microstructural properties of acid milk gels. In order to investigate the interactions of denatured whey protein-casein, the formation of covalent and non-covalent bond namely thiol/disulphide, hydrophobic and electrostatic etc. are reviewed, with the emphasis on acid gelation and final yoghurt texture. This review summarizes the different factors and interactions on the formation of the micelle bound complexes or soluble denatured whey protein/k-casein complexes in heated milk and how these complexes affect the yoghurt properties. This information could be fundamental knowledge for developing a desirable yoghurt texture, may have potential interest for future research.

Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects.

The aim of this study was to determine the degree of contamination caused by Cryptosporidium oocyts in regularly consumed salad vegetables sold at various wholesale and retail markets in northern part of Bangladesh. A total number of 165 samples of salad vegetables collected from different wholesale and retail markets were examined for detection of Cryptosporidium oocysts using sucrose flotation medium of 1.18 specific gravity and Ziehl Neelsen staining technique with some modifications. Cryptosporidium oocysts were detected in 47 (30%) of the total examined samples. About 40 Tomato, 35 Cucumber, 20 Lettuce, 35 Carrot and 35 Mint’s leaf samples were examined while Lettuce had the highest (40%) contamination rate followed by Tomato (32.5%), Carrot (31.4%), Cucumber (25.7%), and Mint’s leaf (22.8%). There was no significant difference (x2 = 2.278; p

Here, we investigate the effects of pH adjustment before heating milk on the textural properties of whey protein enriched yogurt. Whey protein enriched skim milk was adjusted to pH of 6.3, 6.7, and 7.1 followed by heating at 85 °C for 30 min. Yogurts prepared from milk heated at pH 6.7 showed remarkably higher G′ (storage modulus) values, water holding capacity and firmness compared to those prepared from unheated milk, or milk heated at pH 6.3 or 7.1. A relatively more compact protein network was observed in the yogurt made from milk heated at pH 6.7. Heating milk at pH 6.7 formed both whey protein-associated casein micelles (WPA-CM) and soluble whey protein/κ-casein complexes (SWP-CC), resulting in the presence of numerous aggregating particles, which was responsible for the firmer yogurt gel. Heating milk at pH 7.1 (mostly SWP-CC) resulted in higher yogurt firmness than heating at pH 6.3 (mostly WPA-CM). Practical applications Whey protein fortification and heating milk improve yogurt texture. However, different pH values of the milk before heating and whey protein fortification affect the properties of the yogurt. Variation of milk pH before heat treatment affects the degree of association between denatured whey proteins and casein micelles. As a result, inconsistencies occur in yogurt gel texture. This study showed that yogurt made from milk heated at pH 6.7 had increased firmness and water holding capacity compared with that when the milk was heated at pH 6.3 or 7.1. The pH of milk naturally changes slightly throughout the year, which in turn might affect yogurt firmness. Therefore, milk pH is an important parameter which needs to be adjusted to produce uniform quality yogurt to obtain a well-accepted commercial product.

The chemical, physico-chemical and functional properties of flour and starch from three varieties of jackfruit seed were analyzed in this study. Starch was isolated using distilled water, alkaline and α-amylase enzyme. All varieties of jackfruit seed flour had moisture content 6.28-9.16%, protein 9.19-11.34%, fat 1.18-1.40%, ash 1.53-2.66%, amylose 26.49%-30.21% and starch contents 81.05%-82.52%. Gala variety had highest amount of water soluble index, swelling water capacity and water absorption index than Khaja and Durasha varieties. On the other hand, isolated starch varied 8.39 to 12.20% moisture, 1.09 to 3.67% protein, 1.18 to 1.40% fat, 0.03 to 0.59% ash content. Starch isolated with distilled water had higher protein content, yield, amylose and total starch than starch isolated with alkaline and enzyme. However, purity was depended on the variety and extraction conditions. Enzymatic method gave highest amount of water absorption index and water soluble index as compared to distilled water and alkaline method. Results from this study suggest that jackfruit seed flour can be used as partial replacement of wheat flour and good source of starch.