Lactose-free Products Research Articles

Whole soybean protein extraction processes: A review

Abstract Soybeans are an important raw material for those seeking vegan, lactose-free products, such as soymilk and tofu. The aim of this review article is to provide an overview of aqueous extraction of protein and other desirable components from whole soybeans. Firstly, a discussion over the microstructure of the soybean is held, including a summary of protein localisation and properties. A detailed review of common whole soybean extraction process is then given, along with extraction process parameters and process intensification steps that can improve yield. A novel extraction model is presented, based on a mass balance of the water phases. The extraction model reveals separation as the main limitation for protein recovery during aqueous soy protein extraction due to the high amount of okara waste stream and its high moisture content. Industrial relevance Typically, the extraction of protein from an intermediate soy-protein ingredient is studied at lab-scale. Within industry, aqueous extract from whole soybeans is commonly used for making consumer products containing both soy protein and soybean oil, and this has been the focus of this review. Key extraction process parameters are presented and challenges of each extraction step are given for the whole soybean extraction process. A novel model for determining the separation efficiency has been presented, which is useful for many other extraction systems that contain components of interest in high amounts of waste stream.

Lactose-free frozen yogurt: production and characteristics.

Nowadays, consumer demand is driving better and more nutritious dairy products. Changing from traditional to new lactose-free products poses technological challenges for the food industry in order to maintain or improve their food characteristics and consumer preferences. This study investigates the production of lactose-free frozen yogurt by enzymati- cally hydrolysis of lactose, and its influence on the final product characteristics. In the case of lactose-free products, commercial Ha-lactase® was used for hydrolysis, and the reaction occurred simultaneously with fermentation. The effect of lactose hydrolysis on the physicochemical properties, texture, viscosity, overrun and sensory attributes in the final product was investigated. After yogurt maturation, the acidity of the lactose-free product was significantly higher than in the control, suggesting that breaking down lactose enhances the fermentation process. Lactose-free frozen yogurt had significantly lower hardness and stickiness and higher viscosity than control frozen yogurt. Moreover, lactose hydrolysis promoted a smooth and creamy consistency, whereas in the case of conventional prod- ucts a coarse structure, due to the presence of large ice crystals, was identified. Hydrolysis of lactose also improved the sweetness and brightness of frozen yogurt. The improved textural properties of lactose-free product results from the fact that monosaccharides produced during lactose hydrolysis depress the freezing point of the mix, which enables product with softer structure and bigger resistance to ice recrystallization to be obtained. The study showed that lactose-free frozen yogurt may be used successfully for production of novel lactose-free frozen desserts. Lactose hydrolysis improves the texture and viscosity of the product,     as well as enhancing its sensory quality.

Recent advances on lactose intolerance: Tolerance thresholds and currently available answers

ABSTRACTThe genetically programmed reduction in lactase activity during adulthood affects 70% of the world adult population and can cause severe digestive disorders, which are the sign of lactose intolerance. Lactose intolerance symptoms vary depending on the residual lactase activity, the small bowel transit time, and especially the amount of ingested lactose. To formulate dairy products suitable for the vast majority of lactose intolerants, it is essential to define lactose intolerance threshold. A recent meta-analysis permitted to show that almost all lactose intolerants tolerate 12 g of lactose in one intake and approximately 18 g of lactose spread over the day. The prevalence and severity of lactose intolerance are probably overestimated by the general public. This misconception usually leads to an unnecessary reduction of dairy foodstuff consumption. Nevertheless, dairy products are essential for health mainly due to their calcium content and the positive influence of probiotic bacteria. The formulation of dairy products suitable for most intolerant and suspicious subjects seems necessary. The use of exogenous enzyme preparations, as well as the consumption of lactose-free products or products rich in probiotic bacteria are proposed as symptom-reducing strategies.

Sources of β-galactosidase and its applications in food industry.

The enzyme β-galactosidases have been isolated from various sources such as bacteria, fungi, yeast, vegetables, and recombinant sources. This enzyme holds importance due to its wide applications in food industries to manufacture lactose-hydrolyzed products for lactose-intolerant people and the formation of glycosylated products. Absorption of undigested lactose in small intestine requires the activity of this enzyme; hence, the deficiency of this enzyme leads to lactose intolerance. Lactose intolerance affects around 70% of world's adult population, while the prevalence rate of lactose intolerance is 60% in Pakistan. β-Galactosidases are not only used to manufacture lactose-free products but also employed to treat whey, and used in prebiotics. This review focuses on various sources of β-galactosidase and highlights the importance of β-galactosidases in food industries.

Production of Farmstead Lactose-Free Pecorino di Osilo and Ricotta Cheeses from Sheep's Milk.

The present work was aimed to define and validate farmstead production of lactose-free Pecorino di Osilo cheese, fresh ricotta cheese, and salted and smoked ricotta cheese (Ricotta mustia). The enzymatic activity of the commercial preparation containing lactase (1.1 g/mL), preliminarily tested using a spectrophotometric titration, showed activity equal to 4950±40 neutral lactase unit/g. The amount of lactase required to obtain the lactose-free milk was then established in triplicate laboratory trials, by adding the enzyme at concentrations of 0.7, 0.9 and 1.1 g/L in flasks containing 160 mL of raw sheep’s milk. Samples were incubated under conditions expected during milk storage and cheese-making. The residual lactose content in milk was determined by enzymatic method. The addition of lactase at concentration of 1.1 g/L of milk reduced the lactose concentration below the limit of detection (LOD) of 0.06 g/L. The procedure was validated at a dairy farm, using three different batches of bulk raw sheep’s lactose-free milk that were transformed into Pecorino di Osilo cheese. The resulting whey was used to produce fresh ricotta and Ricotta mustia cheese. Raw milk and whey samples were always below lactose detection limit. The residual lactose was measured in Pecorino di Osilo cheese, after 24 hours and 30 days from production; in fresh ricotta cheese, after 48 hours; in Ricotta mustia cheese after 7 days. The determination of lactose content in cheese samples was conducted by a gas chromatography-flame ionization detection method, which showed a LOD and limit of quantification respectively of 1.8 and 5.6 mg/kg for cheese, and 1.35 and 4.2 mg/kg for both ricotta cheeses. The lactose concentration was always below the relevant LOD values in all samples. The mean concentration of galactose and glucose were respectively 13,000±2000 and 11,000±2000 mg/kg in fresh Pecorino di Osilo, 1100±300 and 1200±300 mg/kg in fresh ricotta, and 950±400 and 750±250 mg/kg in Ricotta mustia. The results of the present study showed that the production of farmstead lactose-free Pecorino di Osilo cheese and ricotta cheeses from raw sheep’s milk is easily achievable. The main issue for farmstead production of artisanal lactose-free products is the implementation of permanent procedures based on hazard-analysis and critical control principles aimed at guaranteeing the effectiveness of the process and at acquiring analytical evidences to demonstrate the fulfilment of law requirements for labelling.

Measuring the lactose content in milk

Raman spectroscopy has become a powerful and popular tool for food systems analyses lately. Based on characteristic vibrations of the studied material, the information on its content and structure can be answered. In the paper, Raman spectroscopy is studied for a purpose of lactose content in milk assessment. Lactose, the milk disaccharide, in a human organism decomposes during digestion by the act of enzyme lactase to more easily digestible monosaccharides – glucose and galactose. The lack of enzyme lactase causes symptoms of lactose intolerance what limits lactose-intolerant individuals in the intake of milk and dairy products. Lactose-free products in the diet can be a solution. Raman spectroscopy offers rapid measurement independent of the number of chemicals and other in the paper listed benefits. Raman spectra of lactose, glucose and galactose exhibit enough differences to distinguish the content of lactose in milk. C-O-H bending mode at 1087 cm -1 is used for lactose quantification. The method accuracy for measuring content of lactose was tested on dried milk droplets. Evaluation of the spectroscopic data was related to two different substances - phenylalanine contained generally in the milk and crystal violet used as an internal standard.

Lactose avoidance for young children with acute diarrhea.

For the current issue of the Journal, we asked Drs Natasha Saunders and Jeremy Friedman to comment on and put into context the recent Cochrane Review on avoiding or reducing intake of lactose-containing milk or milk products for reducing the duration and severity of acute diarrhea in children. Background Young children with acute diarrhea, typically due to infectious gastroenteritis, may temporarily stop producing lactase, the intestinal enzyme that digests lactose. Thus, they may not digest lactose, the main sugar in milk, and this may worsen or prolong the diarrheal illness. However, there is uncertainty regarding whether avoiding lactose-containing milk or milk products helps young children recover from acute diarrhea more quickly. Methods Search strategy: The authors performed a search of the Cochrane Infectious Diseases Group Specialized Register (May 14, 2013), Cochrane Central Register of Controlled Trials (CENTRAL) published in The Cochrane Library (Issue 4, 2013), MEDLINE (1996 to May 14, 2013), EMBASE (1974 to May 14, 2013), LILACS (1982 to May 14, 2013) and the reference lists of potentially relevant trials and key conference proceedings, and wrote to individuals and organizations in the field. Selection criteria: Randomized or quasi-randomized controlled trials that assessed the effects of avoiding or reducing exposure to lactose in young children <5 years of age with acute diarrhea. Data analysis: Data were extracted using the standard methods of the Cochrane Infectious Diseases Group, and two review authors independently evaluated trial quality and data extraction. Continuous outcomes were compared using mean difference (MD) and dichotomous outcomes were compared using the risk ratio (RR). All results are presented with 95% CIs; the quality of evidence was assessed using the GRADE approach. Results Thirty-three trials enrolling 2973 children with acute diarrhea were included. Twenty-nine trials were exclusively conducted on inpatients, all from high- or middle-income countries. Fifteen trials included children <12 months of age, and 22 excluded children who were being breastfed. Compared with lactose-containing milk, milk products or foodstuffs, lactose-free products may reduce the duration of diarrhea by a mean of approximately 18 h (MD −17.77 [95% CI −25.32 to −10.21]; 16 trials, 1467 participants, low-quality evidence). Lactose-free products likely also reduce treatment failure (defined variously as continued or worsening diarrhea or vomiting, the need for additional rehydration therapy or continuing weight loss) by approximately one-half (RR 0.52 [95% CI 0.39 to 0.68]; 18 trials, 1470 participants, moderate-quality evidence). Diluted lactose-containing milk has not been shown to reduce the duration of diarrhea compared with undiluted milk or milk products (five trials, 417 participants, low-quality evidence), but may reduce the risk of treatment failure (RR 0.65 [95% CI 0.45 to 0.94]; nine trials, 687 participants, low-quality evidence). Conclusions In young children with acute diarrhea who are not predominantly breast-fed, a change to a lactose-free diet may result in earlier resolution of acute diarrhea and reduce treatment failure. Diluting lactose-containing formulas may also have some benefits; however, further trials are required to confirm this finding. There are no trials from low-income countries, where mortality for diarrhea is high and malnutrition is more common. The full text of the Cochrane Review is available in The Cochrane Library (1).

Lactose avoidance for young children with acute diarrhoea.

Young children with acute diarrhoea, typically due to infectious gastroenteritis, may temporarily stop producing lactase, the intestinal enzyme that digests lactose. This means they may not digest lactose, the main sugar in milk, and this may worsen or prolong the diarrhoeal illness. However, there is uncertainty whether avoiding lactose-containing milk or milk products helps young children recover from acute diarrhoea more quickly. To assess if avoiding or reducing intake of lactose-containing milk or milk products shortens the duration and severity of illness in young children with acute diarrhoea. We also sought other indicators of morbidity and overall mortality. We searched the Cochrane Infectious Diseases Group Specialized Register (14 May 2013), Cochrane Central Register of Controlled Trials (CENTRAL) published in The Cochrane Library (Issue 4, 2013), MEDLINE (1996 to 14 May 2013), EMBASE (1974 to 14 May 2013), and LILACS (1982 to 14 May 2013), and the reference lists of potentially relevant trials, key conference proceedings, and wrote to individuals and organizations in the field. Randomized or quasi-randomized controlled trials that assessed the effects of avoiding or reducing exposure to lactose in young children under five years with acute diarrhoea. We extracted data using the standard methods of the Cochrane Infectious Diseases Group, and two review authors independently evaluated trial quality and data extraction. Continuous outcomes were compared using mean difference (MD), and dichotomous outcomes using the risk ratio (RR). We presented all results with 95% confidence intervals (CI) and assessed the quality of evidence using the GRADE approach. We included 33 trials enrolling 2973 children with acute diarrhoea. Twenty-nine trials were exclusively conducted on inpatients, all from high- or middle-income countries. Fifteen trials included children aged below 12 months, and 22 excluded children who were being breast-fed.Compared to lactose-containing milk, milk products, or foodstuffs, lactose-free products may reduce the duration of diarrhoea by an average of about 18 hours (MD -17.77, 95% CI -25.32 to -10.21, 16 trials, 1467 participants, low quality evidence). Lactose-free products probably also reduce treatment failure (defined variously as continued or worsening diarrhoea or vomiting, the need for additional rehydration therapy, or continuing weight loss) by around a half (RR 0.52, 95% CI 0.39 to 0.68, 18 trials, 1470 participants, moderate quality evidence).Diluted lactose-containing milk has not been shown to reduce the duration of diarrhoea compared to undiluted milk or milk products (five trials, 417 participants, low quality evidence), but may reduce the risk of treatment failure (RR 0.65, 95% CI 0.45 to 0.94, nine trials, 687 participants, low quality evidence). In young children with acute diarrhoea who are not predominantly breast-fed, change to a lactose-free diet may result in earlier resolution of acute diarrhoea and reduce treatment failure. Diluting lactose-containing formulas may also have some benefits but further trials are required to have confidence in this finding. There are no trials from low-income countries, where mortality for diarrhoea is high, and malnutrition is more common.

Su2076 Weight Regain After Roux-en-Y Gastric Bypass Surgery Is Associated With Dysphagia Symptoms but Not Manometric Findings

Background: It has been suggested that a diet low in fermentable short chain carbohydrates, FODMAPs (Fermentable Oligo-Di-Monosaccharides and Polyols) can reduce gastrointestinal symptoms in patients with irritable bowel syndrome (IBS) (Gibson & Shepherd Am J Gastroenterol 2012). However, the intake of FODMAPs in IBS patients compared to the general population has not been studied. Aim: To measure the intake of FODMAPs in patients with IBS in comparison with the general population, and to determine the major sources of FODMAPs in the diet of IBS patients. Method: We included 115 patients with IBS according to the Rome III criteria (39.1±13.0 (mean± SD) years; 88 females) referred to our outpatient clinic. They completed a 4-days food registration record, which was compared with 115 age-and gender matched control subjects from a nation-wide dietary survey. A database including content of fructose, fructan, lactose, galacto-oligosaccharides (GOS) and polyols in 1700 food items was developed specifically for this study to determine the intake of FODMAPs. Results:The IBS patients had significantly lower intake of FODMAPs than the control group from the general population (30.91±14.3 vs.34.56±12.67 g/day; p,0.05). The intake of lactose was lower in IBS patients compared to controls (10.47±8.22) vs.13.70±8.29 g/day; p, 0.001), while polyol intake was significantly higher in the IBS group (1.70±1.87 vs.1.25±1.64 g/day; p,0.05). However, there were no statistically significant differences regarding the intake of fructose (14.18±7.63 vs.15.28±6.93 g/day; p=0.24) fructan (3.91±1.73 vs.3.78±1.67g/day; p=0.55) or GOS (0.63±0.61vs. 0.53±0.56 g/day; p=0.16) between IBS patients and control subjects. The major food sources with naturally occurring fructan and contributing to the intake of fructan in both groups were onion, garlic, wheat and rye. Fruit drinks/-juices and apples were the main contributors to the fructose intake. The richest sources of polyols in the IBS group were pears and sugar-free sweets and in the controls pears, apples and sugar-free sweets. Legumes and wheat-products were the major contributors to intake of GOS in both groups. IBS patients ate less dairy products and replaced 15% of lactose containing products with lactose-free, soy or oat products. The patients ingested half the amount of fruit drinks in comparison to the control group, and their intake of wheat containing food items was also lower than for the control group. Intake of legumes and onions were equal in both groups except for garlic that was more frequently consumed in the IBS group. Conclusion: Intake of FODMAPs seems to be lower in IBS patients than in the general population, and this was mainly explained by a reduction of the intake of lactose containing food items. Further studies assessing the role of intake of FODMAPs for symptoms in IBS patients are needed.

Effects of a fibre-enriched milk drink on insulin and glucose levels in healthy subjects

BackgroundThe glycaemic response to foods is dependent on the quality and content of carbohydrates. Carbohydrates in the form of dietary fibre have favourable effects on insulin and glucose metabolism and may help to control energy intake. Dairy products have a relatively low carbohydrate content, and most of the carbohydrate is in the form of lactose which causes gastrointestinal symptoms in part of the population. In order to avoid these symptoms, dairy products can be replaced with lactose-free dairy products which are on the market in many parts of the world. However, the effects of lactose-free products on insulin and glucose metabolism have not been studied.MethodsIn the present study, we investigated the effects of 1) a lactose-free milk drink, 2) a novel fibre-enriched, fat- and lactose-free milk drink and 3) normal fat-free milk on serum glucose and insulin levels and satiety using a randomized block design. Following an overnight fast, 26 healthy volunteers ingested 200 ml of one of these drinks on three non-consecutive days. Insulin and glucose levels and subjective satiety ratings were measured before the ingestion of the milk product and 20, 40, 60, 120 and 180 minutes after ingestion. The responses were calculated as the area under the curve subtracted by the baseline value (AUC minus baseline).ResultsThe insulin response was significantly lower for the fibre-enriched milk drink than it was for the other milk products (AUC, P = 0.007). There were no differences in the response for glucose or in the AUC for the subjective satiety ratings between the studied milk products.ConclusionThe present results suggest that this novel milk drink could have positive effects on insulin response.

Sensory characteristics of commercial lactose-free milks manufactured in the United States

This study determined the sensory characteristics of ultrapasteurized (UP) lactose-free milk of different fat contents, and compared them with regular milk. Nine milk samples (six UP lactose-free and three regular) containing 0, 2 or 3 g milkfat/100 mL were tested by a descriptive panel. A consumer test with three UP lactose-free milk and three regular samples was also conducted. The skim milks were found to be lacking in freshness and the dairy notes were lower compared to the higher-fat-content milks. The UP lactose-free milks were different from the regular milk because of higher intensities of cooked, processed, and sweet attributes. UP lactose-free milks tended to score higher than the regular milks at the same fat content for dairy-related attributes, but this difference was not significant for the reduced-fat milks. Although majority of the consumers in the present study were aware that UP lactose-free milks existed in the market, only few had tasted them before. The higher intensities of cooked and sweet flavor attributes in the UP lactose-free milks might be a hindrance to their consumption by the lactose-intolerant population. More efforts are needed from the dairy industry to develop better lactose-free products and to educate consumers about lactose-free dairy products.

Irritable bowel syndrome: symptomatic treatment versus integrative psychotherapy

AbstractIrritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder thought to affect 10% to 20% of the population worldwide. Essentially the paper is in two parts. The first part of the paper investigates the world literature and a variety of up to date treatment approaches which, with the exception of cognitive‐behavioural therapy (CBT) which also has beneficial effects on patients' overall mood and bloating, are designed to manage individual symptoms of IBS. The review examines the efficacy of pharmaceutical agents (antispasmodics, antidepressants, antidiarrhoeals and the new serotonergic modifying agonists/antagonists), dietary control (fibre, lactose free products, partially hydrolyzed guar gum, peppermint oil, prebiotics and probiotics), CBT (with or without the use of an audiotape) and the standard gut‐directed hypnotherapy approach of the Manchester Model.In the second half, in sharp contrast to the symptomatic treatments, the authors give a detailed account of a 54‐year‐old female patient with refractory IBS in a setting of a phobic anxiety state. The treatment approach – a combination of psychotherapy and hypnosis – was designed to effect a complete recovery rather than to manage individual symptoms. This case study exemplifies the complex nature of IBS symptoms in relation to the patient's emotions. It was necessary for her to work through these emotional problems so that she did not need to express her intense hostility through her bowels. These problems were expressed both in the psychotherapy sessions as well as in the hypnotherapy. The patient made a full recovery and this was maintained at the follow‐up a year later. Copyright © 2007 British Society of Experimental &amp; Clinical Hypnosis. Published by John Wiley &amp; Sons, Ltd.

The Palatability of Corn Chowder Prepared With Blended Tofu

LEARNING OUTCOME: The effects of using blended tofu in a corn chowder recipe The purpose of the study was to determine the acceptability of corn chowder when blended tofu is used for some or all of the milk in a corn chowder recipe. In recent years, the use of soy products in the United States has become a major trend. Tofu, a derivative of soybeans, is an inexpensive source of high protein which is also low in saturated fat and cholesterol. Soy foods are now being recognized as having the potential roles in the prevention and treatment of chronic diseases, such as heart disease and cancer. Also, lactose-free products would be a healthy alternative for lactose intolerant people. In this study, tofu puree was prepared by beating 8 oz soft tofu with 1 T water and 1 T vegetable broth until smooth. A standard highly seasoned corn chowder was made with 3/4 cup low-fat milk and 3/4 cup vegetable broth. The following variations were made: A) 100% (3/4 cup) milk, 0% tofu; B) 73% (1/2 cup) milk, 27% (3 T) tofu; C) 57% (1/3 cup) milk, 43% (1/4 cup) tofu; D) 43% (1/4 cup) milk, 57% (1/3 cup) tofu; E) 0% milk, 100% (1/2 cup) tofu. Sensory evaluations showed that Sample E with 100% tofu puree had the highest flavor and acceptability scores with the least off-flavor. Consistency and color scores were acceptable. Results showed that acceptable corn chowder products can be successfully prepared with only tofu puree and no milk.