Bacteriocin production by lactic acid bacteria using ice cream co-product as the fermentation substrate.

Ice cream manufacture commonly results in the accumulation of wasted product that contains valuable food-grade quality components, including fat, carbohydrates, and protein. Methods have been developed for recovering the fat from this waste stream, but this results in the generation of a co-product rich in fermentable carbohydrates. This study aimed to investigate the potential for using this co-product as a fermentation substrate for production of antimicrobial peptides, called bacteriocins, by dairy starter cultures. Results showed that Streptococcus thermophilus B59671 and Lactococcus lactis 11454 produced the broad-spectrum bacteriocins thermophilin 110 and nisin, respectively, when the fermentation substrate was melted ice cream, or a co-product generated by a modified butter churning technique. Bacteriocin production varied depending on the brand and variety of vanilla ice cream used in this study. When an alternate enzyme-assisted fat extraction technique was used, S. thermophilus metabolism was impaired within the resulting co-product, and thermophilin 110 production was not observed. Lactococcus lactis was still able to grow in this co-product, but antimicrobial activity was not observed. Results from this study suggest the co-product generated when using the churning technique is a better choice to use as a base medium for future studies to optimize bacteriocin production.

Probiotic-Enriched Ice Cream with Fermented White Kidney Bean Homogenate: Survival, Antioxidant Activity, and Potential for Future Health Benefits.

This study investigated a novel probiotic-enriched ice cream containing fermented white kidney bean homogenate to explore its potential health benefits in the future. We assessed the viability of various probiotic strains during ice cream production and storage, focusing on their potential to reach the gut, and evaluated overall antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and total polyphenol content (TPC) assays. The incorporation of fermented white bean homogenate significantly increased antioxidant capacity compared to the control group. Notably, strains such as Lacticaseibacillus rhamnosus GG and Lactiplantibacillus plantarum 299v demonstrated the most pronounced effects on antioxidant activity, suggesting potential synergistic benefits between probiotics and bioactive compounds in fermented white beans. Although all probiotic strains experienced decreased viability during storage, certain strains, particularly L. plantarum 299v and Lacticaseibacillus casei DN-114001, showed promising survival rates even after 6 months. These results suggest the potential for developing probiotic ice cream containing viable bacteria capable of reaching the gut and contributing to a healthy gut microbiota. Overall, this study highlights the potential of probiotic-enriched ice cream with fermented white kidney bean homogenate to combine the established benefits of probiotics for gut health with the enjoyment of consuming ice cream.

Imaging the 3D microstructural changes of ice cream during meltdown.

Ice cream is a multiphase frozen dessert that often melts during distribution and upon consumption. The meltdown phenomenon is one of the concerns in the quality preservation of ice cream for consumer convenience in the frozen food industry. In this context, X-ray tomography was used to visualise and quantify 3D ice crystal and air bubble evolution during the meltdown of ice cream. Two ice cream products, namely I and II, with varying air volume fractions, were evaluated for this study. The results indicated a small mean diameter of 66.43 ± 2.07 µm at 0 min and decreased to 45.74 ± 3.92 µm during 10 min of the meltdown of ice cream II. A large mean diameter of ice crystals of 75.02 ± 3.14 µm was found in ice cream I, at 0 min that decreased significantly (p < 0.05) to 54.30 ± 2.63 µm during 10 min of the meltdown. The air bubbles were also observed to decrease in mean diameter. The 3D datasets on the ice crystals and air bubbles described in this work provide more insight into the 3D microstructural evolution during the meltdown and are useful in controlling the sensory quality attributes of ice cream desserts.

Fruit-based vegan ice cream-type frozen dessert with aquafaba: effect of fruit types on quality parameters.

"Aquafaba", defined as legume cooking water, has a feature that can be used in various formulations as an egg and milk alternative in vegan products and improves functional properties such as foaming, emulsifying and gelling. In this study, it was aimed to investigate the usability of aquafaba in ice cream type frozen desserts containing different fruit purees (strawberry, nectarine and banana) by using its foaming capacity. Rheological properties, microstructure, overrun, melting characteristics, color measurement, dry matter, and sensory properties were investigated in different fruit-based frozen dessert samples. The brix value, density, protein content, foaming capacity (FC) and foaming stability (FS), flow behavior index, consistency coefficient, and overrun of aquafaba were determined as 7.1 ± 0°Bx, 1.022 ± 0.011 g/ml, 1.51 ± 0.41%, 85 ± 0% FC and 81 ± 0.23% FS, between 0.28 and 0.64, between 8.68 and 41.30 Pa·sn, between 116.75 and 395.93%, respectively. The dry matter content of the strawberry, nectarine, and banana-based dessert samples ranged between 17 and 48%, 20-49%, 25-50%, and the first dropping times were determined between 348 and 1538 s, 369-1689 s and 435-1985 s, respectively. As a result, cooking liquid leftover aquafaba can be used as a suitable raw material in the production of an alternative ice cream type frozen dessert for individuals with milk allergy, lactose intolerance or who prefer a vegan diet. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05885-y.

Listeria monocytogenes Illness and Deaths Associated With Ongoing Contamination of a Multiregional Brand of Ice Cream Products, United States, 2010-2015.

BACKGROUND: Frozen foods have rarely been linked to Listeria monocytogenes illness. We describe an outbreak investigation prompted by both hospital clustering of illnesses and product testing. METHODS: We identified outbreak-associated listeriosis cases using whole-genome sequencing (WGS), product testing results, and epidemiologic linkage to cases in the same Kansas hospital. We reviewed hospital medical and dietary records, product invoices, and molecular subtyping results. Federal and state officials tested product and environmental samples for L. monocytogenes. RESULTS: Kansas officials were investigating 5 cases of listeriosis at a single hospital when, simultaneously, unrelated sampling for a study in South Carolina identified L. monocytogenes in Company A ice cream products made in Texas. Isolates from 4 patients and Company A products were closely related by WGS, and the 4 patients with known exposures had consumed milkshakes made with Company A ice cream while hospitalized. Further testing identified L. monocytogenes in ice cream produced in a second Company A production facility in Oklahoma; these isolates were closely related by WGS to those from 5 patients in 3 other states. These 10 illnesses, involving 3 deaths, occurred from 2010 through 2015. Company A ultimately recalled all products. CONCLUSIONS: In this US outbreak of listeriosis linked to a widely distributed brand of ice cream, WGS and product sampling helped link cases spanning 5 years to 2 production facilities, indicating longstanding contamination. Comprehensive sanitation controls and environmental and product testing for L. monocytogenes with regulatory oversight should be implemented for ice cream production.

Psychrotrophic Bacteria Equipped with Virulence and Colonization Traits Populate the Ice Cream Manufacturing Environment.

Several microbial taxa have been associated with food processing facilities, and they might resist by attaching on tools and equipment even after sanitation procedures, producing biofilms that adhere to the surfaces and might embed other microorganisms, including spoilers and pathogens. There is increasing evidence that these communities can be transferred to the final product. To explore the microbial contamination routes in a facility producing ice creams, we collected foods and environmental swabs from industrial surfaces of equipment and tools and performed taxonomic and functional analyses of the microbial DNA extracted from the environmental samples. Our results suggest that complex communities dominated by psychrotrophic bacteria (e.g., Pseudomonas and Acinetobacter spp.) inhabit the food processing environment, and we demonstrate that these communities might be transferred from the surfaces to the products. Functional analysis performed on environmental samples highlighted the presence of several genes linked to antimicrobial resistance and adherence on abiotic surfaces; such genes were more abundant on food contact (FC) than on other surfaces. Metagenome-assembled genomes (MAGs) of Pseudomonas stutzeri showed genes linked with biofilm formation and motility, which are surely linked to colonizing capabilities in the processing lines. The study highlights clear potential advantages of applying microbiome mapping in the food industry for source tracking of microbial contamination and for planning appropriate ad hoc sanitization strategies. IMPORTANCE Several microbial species might permanently establish in food processing facilities, thus contributing to food loss. In fact, food contact surfaces might transfer microorganisms to intermediates and products, potentially representing a hazard to human health. In this work, we provide evidence of the existence of complex microbial communities overcoming sanitation in an ice cream-producing facility. These communities harbored several genes that could potentially lead to attachment to surfaces and antimicrobial resistance. Also, prediction of routes of contamination showed that several potential spoilage taxa might end up in the final product. Importantly, in this work, we show that mapping the environmental microbiome is a high-resolution technique that might help food business operators ensure food quality and safety through detection of potentially hazardous microorganisms.

Partition of milk phospholipids during ice cream manufacturing.

The distribution of phospholipids (PL) within the fat and serum phase of ice cream manufacturing was evaluated through partition coefficients (KPL) after mixing, pasteurization, freezing, and hardening. Ice creams containing about 40.41 ± 3.45 (± standard deviation; control formulation) and 112.29 ± 9.06 (enriched PL formulation) mg of PL per g of fat were formulated with nonfat dry milk and ß-serum, respectively. Overall, the KPL were lower than 1, indicating that the PL were predominantly found in the fat phase, and only a small amount was left in the serum and sediment. Confocal micrographs visually confirmed this generalization. The addition of PL significantly increased the viscosity of the mixes between 4- and 9-fold, depending on the shear rate. Additionally, mixes containing high PL exhibited higher yield stress than those formulated with low PL (0.15 ± 0.09 and 0.016 ± 0.08 Pa, respectively). Ice creams with high PL delayed the onset of meltdown and exhibited a slower rate of a meltdown than low-PL ice creams (18.53 ± 0.57 and 14.83 ± 0.85 min, and 1.01 ± 0.05 and 0.71 ± 0.04% min-1, respectively). This study provides useful guidelines for manufacturing ice cream enriched in milk PL. Additionally, the use of ß-serum, a byproduct stream, as a source of PL is illustrated. The development will require studying the sensorial description of the product as well as consumer acceptance.

Application of Gas-Liquid Microextraction (GLME)/GC-MS for Flavour and Fragrance in Ice Cream Detection and Composition Analysis.

Under gas-liquid microextraction (GLME) operating conditions (extraction temperature 270 °C, extraction time 7 min, condensation temperature -2 °C, and carrier nitrogen gas speed 2.5 mL/min), ice cream samples, as a representative food, were pre-treated. The volatile aroma components of each sample was qualitatively analysed using GC-MS. The principal component analysis was conducted to classify the functional groups, which showed that alcohols, acids, esters, ketones, and aldehydes were the main compounds responsible for the aroma of ice cream. It was found that furan-3-carboxaldehyde, 3-furanmethanol, 2(5H)-furanone, 5-methylfuranal, 2,5-diformylfuran, 3-hydroxy-2-methyl-4-pyrone, 5-hydroxymethylfurfural, ethyl maltol, and glycerol were routinely used flavour ingredients in ice cream.

Study of Water Freezing in Low-Fat Milky Ice Cream with Oat ß-Glucan and Its Influence on Quality Indicators.

The work is devoted to the study of the functional and technological properties of oat ß-glucan in low-fat milky ice cream (2% fat) in comparison with the stabilization system Cremodan® SI 320. ß-glucan (0.5%) has a greater effect on the cryoscopic temperature of ice cream mixes than Cremodan® SI 320 in the same amount (decrease by 0.166 °C vs. 0.078 °C), which inhibits the freezing process of free water in ice cream during technological processing in the temperature range from -5 to -10 °C. Microscopy of ice cream samples after freezing and hardening shows the ability of ß-glucan to form a greater number of energy bonds due to specific interaction with milk proteins. Analysis of the microstructure of ice cream samples during 28 d of storage confirms the ability of oat ß-glucan to suppress the growth of ice crystals more effectively than Cremodan® SI 320. Oat ß-glucan gives ice cream a rich creamy taste, increases overrun and resistance to melting, which brings this type of frozen dessert closer to a full-fat analogue (10% fat).

Effects of Partial Replacement of Sugar with Fig Syrup on the Survival of Bacillus coagulans and the Physicochemical Properties of Probiotic Ice Cream.

Research background: Various sectors of the food industry demand the enrichment of food with functional compounds. Probiotic products with valuable nutritional and therapeutic properties have attracted great attention in the fields of industry, nutrition and medicine. The aim of the present study is to investigate the sensory and physicochemical properties of probiotic ice cream containing fig syrup and to evaluate the survival of Bacillus coagulans after 90 days of storage at -18 °C. Experimental approach: In this study, four experimental groups of ice cream were produced as follows: plain dairy ice cream (without additives), ice cream containing 109 CFU/g B. coagulans, ice cream containing 25 % fig syrup as sugar substitute and ice cream containing 25 % fig syrup as sugar substitute and 109 CFU/g B. coagulans. They were stored at -18 °C for 3 months. Texture, pH, acidity and viscosity were analysed and microbial counts were determined after 1, 30, 60 and 90 days of storage. The organoleptic evaluation was carried out on days 1 and 90. Results and conclusions: The results showed that during the initial freezing process and the transformation of the mixture into ice cream, the number of B. coagulans decreased from 109 to 107 CFU/g, without significant changes observed over the 90-day period. No significant changes were found in the sensory and textural properties of the samples either. Replacement of 25 % sugar with fig syrup reduced the pH, increased the acidity of the ice cream and improved their viscosity. In conclusion, the production of functional ice cream using fig syrup and B. coagulans is recommended for their health benefits. Novelty and scientific contribution: The results of this study can be used to prepare functional and healthy foods. Our results suggest that fig syrup has the potential to be used as a natural sweetener or sugar substitute in various products.

Pea (Pisum sativum L.) pod powder as a potential enhancer of probiotic Enterococcus faecium M74 in ice cream and its physicochemical, structural, and sensory effects.

BACKGROUND: In this study, pea (Pisum sativum L.) pod powder (PPP) was incorporated (1% and 3% w/w) into a probiotic ice cream formulation containing Enterococcus faecium M74 to investigate the potential effect of PPP on the probiotic survivability in the ice cream throughout 60 days of frozen storage. Moreover, the produced symbiotic ice creams were evaluated for their physiochemical properties, stability, and sensory acceptability. RESULTS: Incorporation of PPP into ice cream caused significantly (P < 0.05) increased protein and ash content and lower pH values. Besides that, the addition of PPP resulted in ice creams with higher hardness and lower overrun. A significant diminishing was observed in the melting rates of the ice creams as the percentage of PPP increased and storage time progressed. Ice cream with PPP presented lower lightness and higher greenness and yellowness compared with control. All ice creams had viable counts of E. faecium M74 of ≥6 log cfu g-1 during storage and provided the number of viable cells that the probiotic product should contain. On day 60, the viability of E. faecium M74 in ice cream containing 1% PPP (7.64 ± 0.02) was higher than the control (7.28 ± 0.00). Sensory analyses revealed that there was no statistical difference in ice cream with 1% PPP and the control without PPP in terms of general acceptability. CONCLUSION: These results suggest that pea pods, which is a waste product of the pea industry and obtained at zero cost, could be used as a potential prebiotic and an agent to improve technological properties of dairy products. © 2022 Society of Chemical Industry.

The impact of glycerol monostearate's similarity to fats and fatty acid composition of fats on fat crystallization, destabilization, and texture properties of ice cream.

BACKGROUND: Fat significantly affects the properties of ice cream. Prior studies have investigated the correlation between fat crystallization, fat destabilization, and ice cream quality. However, the role of fatty acid composition, the similarity between fat and emulsifier in these characteristics, and their impact on final product quality remains unclear. RESULTS: To investigate the influence of the fatty acid composition of fats, as well as their similarity to glycerol monostearate (GMS), on fat crystallization and destabilization during the aging and freezing stages, ice creams were formulated using a combination of two types of fats (coconut oil and palm olein) in five different ratios. In oil phases, decreased saturation of fatty acids (from 93.38% to 46.69%) and increased similarity to GMS (from 11.96% to 46.01%) caused a reduction in the maximum solid fat content. Moreover, the rise in unsaturated long-chain fatty acids (from 34.61% to 99.57%) and similarity to GMS enhanced the formation of rare and coarse fat crystals, leading to a sparse crystalline network. This, in turn, reduced the crystallization rate and the stiffness of the fat in emulsions. Assuming consistent overrun across all ice creams, the enhanced interactions between fat globules in ice cream improved its hardness, melting properties, and shrinkage. CONCLUSION: The crystalline properties of fat in emulsions were influenced by oil phases, impacting fat destabilization and ultimately enhancing the quality of ice cream. The present study offers valuable insights for the optimization of fat and monoglyceride fatty acid ester selection, with the potential to improve ice cream quality. © 2023 Society of Chemical Industry.

Zygosaccharomyces rouxii is the predominant species responsible for the spoilage of the mix base for ice cream and ethanol is the best inhibitor tested.

A mix base for ice cream (MBIC) is used to produce artisanal or industrial ice creams and desserts and consists of a mixture of different ingredients, including sugar, egg yolk, natural flavors, starch and milk proteins. MBICs, which have chemical-physical characteristics that include a pH of 5.61 and an activity water (Aw) less than or equal to 0.822, are packaged in tin boxes and stored at ambient temperature. Despite the low Aw, MBIC can support osmotolerant and osmophilic yeast growth. The aim of our work was to study the behavior of Zygosaccharomyces rouxii, the main microorganisms responsible of MBIC spoilage, either in the vivo or in a model system in order to inhibit its growth by the selection of antimicrobial agents. Different osmotolerant yeasts belonging to the genus Zygosaccharomyces were isolated and identified from spoiled and unspoiled lots of MBICs. In particular, Z. rouxii was the predominant species responsible for the spoilage, which depended on the high temperature of storage (>20 °C) and was highlighted by the presence of alcohol, esters, acids and gas (CO2), which blew open the tin boxes. To stop spoilage, different antimicrobial compounds were tested: sulfur dioxide, sorbic and benzoic acids and ethanol. However, only 2% v/v ethanol was required to achieve the total inhibition of the Z. rouxii cocktails tested in this work. The use of other antimicrobials cannot be recommended because they were not able to stop yeast spoilage and changed the color and flavor of the products. Conversely, the use of ethanol is suggested because of its extreme effectiveness against osmotolerant yeasts, and the added amount was less than or equal to the taste threshold limit. The MBICs, treated with ethanol, were stable till the end of their shelf-life (6 months).

Prevalence, Antimicrobial Resistance, and Molecular Characteristics of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus from Retail Ice Cream in Shaanxi Province, China.

Staphylococcus aureus (S. aureus) is one of the major opportunistic foodborne pathogens as well as a source of human and animal infections. As surveillance of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) is limited in ice cream, a total of 240 ice cream samples were collected from three cities in Shaanxi province, China, and screened for S. aureus. All isolates were characterized by antimicrobial susceptibility testing, staphylococcal protein A typing, multilocus sequence typing, enterobacterial repetitive intergenic consensus typing, virulence, and resistance genes. S. aureus was recovered from 10 (4.2%) ice cream samples (13 isolates) with average count from 10 to 100 colony-forming units per gram in all cases. Resistance to amoxicillin/clavulanic acid, penicillin, and trimethoprim/sulfamethoxazole (each 100.0%) was most frequently observed, followed by ampicillin (76.9%), erythromycin (46.2%), ceftriaxone (30.8%), and cefoxitin (15.4%). A total of five types of antimicrobial resistance genes were detected, including ß-lactam (blaZ and mecA), macrolide (ermB and ermC), tetracycline (tetK), aminoglycoside [aac(6')/aph(2') and aph(3')-III], and trimethoprim (dfrG). All of the strains harbored at least one staphylococcal enterotoxins gene. The commonly detected virulence genes were selw and hld (100.0%), followed by selx (92.3%); hla (84.6%); pvl (76.9%); seg, sem, and sen (each 38.5%); sei, seo, and hlb (each 30.8%); sea, seb, selu, and sely (each 23.1%); sed, sej, sek, sep, and seq (each 15.4%); and ser (7.7%). ST5-t002, ST7-t091, and ST5225-t4911 (each 15.4%) were the predominant clones, followed by ST5-t045/t105, ST6-t701/t15417, ST25-t078, ST188-t189, and ST398-t034 (each 7.7%). Among the 13 strains of S. aureus, 2 isolates were detected as MRSA (15.4%), and the molecular type belonged to ST5225-IVa-t4911. Using a 98.8% similarity cutoff, the 13 isolates were divided into 5 clusters (I-1 to I-5). These results demonstrated that the prevalence of S. aureus and MRSA was low in ice cream. However, these isolates exhibited a high level of potential pathogenicity, which represents a potential health hazard for consumers.

A novel and secure technique of stemmed acetabular cup implantation in complex hip reconstructions: a comparative study and technical note.

PURPOSE: The stemmed acetabular cup (SAC) can be considered in several complicated situations. This type of prosthesis uses the iliac isthmus, which is most often preserved, thus allowing solid anchorage. Its implantation is prone to mechanical complications intraoperatively, such as extra-isthmic effraction, fracture, and early aseptic loosening. The aim of our study was to compare a new technique using a flexible motorized reamer combined with isthmus catheterization (Group A) versus the standard technique deploying a rigid reamer alone (Group B). MATERIALS AND METHODS: A retrospective analysis was carried out of the SACs implanted at our hospital. The main evaluation criterion was visualization of extra-isthmic effraction (EIE) of the stem. RESULTS: Fifty-six SACs (Integra Lepine®, Genay, France) were implanted, 31 in group A and 25 in group B. The mean follow-up was 21.6 months ± 22.3. This study found fewer EIEs using a flexible motorized reamer (0 versus 5, p = 0.014), less perioperative bleeding (p = 0.054), and less aseptic loosening in group A (p = 0.034). There was no difference in terms of infection or other mechanical complications post-operatively between the two groups. CONCLUSION: Using iliac catheterization combined with a flexible motorized reamer when implanting a SAC helps to avoid EIE and it also appears to reduce complications such as peri-operative bleeding and early aseptic loosening. We recommend use of this surgical technique rather than a rigid reamer alone, and this new technique should allow widespread and more accessible use of this specific type of implant.

ß-Glucan as a Techno-Functional Ingredient in Dairy and Milk-Based Products-A Review.

The article systematizes information about the sources of ß-glucan, its technological functions and practical aspects of its use in dairy and milk-based products. According to the analysis of scientific information, the main characteristics of ß-glucan classifications were considered: the source of origin, chemical structure, and methods of obtention. It has been established that the most popular in the food technology of dairy products are ß-glucans from oat and barley cereal, which exhibit pronounced technological functions in the composition of dairy products (gel formation, high moisture-binding capacity, increased yield of finished products, formation of texture, and original sensory indicators). The expediency of using ß-glucan from yeast and mushrooms as a source of biologically active substances that ensure the functional orientation of the finished product has been revealed. For the first time, information on the use of ß-glucan of various origins in the most common groups of dairy and milk-based products has been systematized. The analytical review has scientific and practical significance for scientists and specialists in the field of food production, in particular dairy products of increased nutritional value.

Shrinkage in frozen desserts.

Shrinkage is a well-documented defect in frozen desserts, yet the root causes and mechanisms remain unknown. Characterized by the loss of volume during storage, shrinkage arose during the mid-twentieth century as production of frozen desserts grew to accommodate a larger market. Early research found that shrinkage was promoted by high protein, solids, and overrun, as well as postproduction factors such as fluctuations in external temperature and pressure. Rather than approaching shrinkage as a cause-and-effect defect as previous approaches have, we employ a physicochemical approach to characterize and understand shrinkage as collapse of the frozen foam caused by destabilization of the dispersed air phase. The interfacial composition and physical properties, as well as the kinetic stability of air cells within the frozen matrix ultimately affect product susceptibility to shrinkage. The mechanism of shrinkage remains unknown, as frozen desserts are highly complex, but is rooted in the physicochemical properties of the frozen foam. Functional ingredients and processing methods that optimize the formation and stabilization of the frozen foam are essential to preventing shrinkage in frozen desserts.

Product development of ice cream stick from raw banana powder.

This research was focused on using raw bananas in place of natural wooden ice cream sticks. The raw bananas were used in a powdered form and then processed to create a substitute for the wooden sticks. A research operation was carried out, experimenting with different proportions of banana powder in a randomized complete block experimental design (RCBD). The properties of interest for the ice cream sticks were hardness, fracturability, and aw of samples, as well as a sensory evaluation. The research showed that ice cream sticks which contained 50-80% raw banana powder with 40% sugar and 40 min of baking resulted in a product with the properties of commonly used wooden ice cream sticks, and that the product also had a good appearance along with positive consumer response. In addition, the maximum shelf life of such ice-cream sticks was 8 days. In the future, development of this product can increase the value of bananas and also reduce the waste of single-use wooden ice cream sticks.

Effect of Hibiscus sabdariffa and Camellia synensis extracts on microbial, antioxidant and sensory properties of ice cream.

Herbal extracts have been widely used by consumers for food fortification and medical purposes worldwide and are focused in traditional medicine in recent years. At this study, we aimed to examine the antimicrobial, antioxidant and sensory characteristics of ice creams fortified with different combinations of Hibiscus sabdariffa and Camellia synensis determined by Design of Experiments software. Levels of 10-100 and 40-400 mg/kg for Hibiscus sabdariffa and Camellia synensis extracts, respectively, were selected and experiments were conducted by central composite design. Generally, 13 runs were introduced by the software and followed in laboratory for analysis. Antimicrobial activity was studied against Escherichia coli and Staphylococcus aureus as indicators of gram negative and gram positive bacteria. Results showed that all combinations were active against both bacteria but Staphylococcus aureus was more sensitive than Escherichia coli. Importantly, Camellia synensis was more effective than Hibiscus sabdariffa in both antimicrobial and antioxidant experiments but sensory panelists selected the sample containing lowest concentrations of both extracts. However, frequent consumption of low-dose fortified dairies with Hibiscus sabdariffa and Camellia synensis could be helpful for consumers interested in functional foods.

Effect of coconut milk, tender coconut and coconut sugar on the physico-chemical and sensory attributes in ice cream.

The investigation was aimed to understand the effect of coconut milk, tender coconut pulp, tender coconut water and coconut sugar on the qualitative attributes of ice cream. Five ice cream formulations were laid out to substitute the major ingredients of ice cream such as, dairy milk and butter with coconut milk, skim milk powder with tender coconut pulp, refined sugar with coconut sugar and potable water with tender coconut water. Two of the formulations were exclusively non-dairy, third one was the standard dairy ice cream, fourth formulation was with the inclusion of coconut sugar in the standard ice cream and the fifth one was standard ice cream with tender coconut and coconut sugar. Proximate composition of the raw materials revealed that coconut milk, tender coconut pulp and coconut sugar can contribute to the solids-non-fat content in ice cream. Significant effect (p< 0.01) was observed on physico-chemical qualities of the mix and ice cream. Total solids, density and total soluble solids of the ice cream mixes were positively correlated. Density, one of the key physical parameters was ranged from 0.98 to 1.13 g/ cm3. Though coconut milk is acidic, the percent titratable values were within the limit. Non- dairy ice cream formulations obtained lower overrun (p < 0.001). There was a negative correlation between percent fat of ice cream and overrun. Crude fat and protein contents of the ice creams were ranged from 10.52-11.62 % and 3.42-4.94 % respectively. Inclusion of coconut products resulted in increased total phenolics and minerals (ash). Non-dairy formulations were preferred over dairy counterpart with respect to flavour and taste during the sensory evaluation carried out with four different age groups. Thus, the study enlightens the potential scope of utilization coconut products in ice cream industry. It also gave a lead towards developing non-dairy/ vegan delicacy on coconut. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05279-y.