Jochen Weiss

University of Hohenheim · Dept. of Food Physics and Meat Science

The influence of storage atmosphere on the color development and myoglobin (Mb) redox state of beef was investigated. Beef samples were packaged in 6 different atmospheres including different degrees of vacuum, levels of oxygen, nitrogen, and a mixture with 20% CO2 and stored at 2°C for 14 days. Over this time, color and reflection of the packaged...

The application of anthocyanins as red colorants in lipid-containing foods such as oil-in-water emulsions is challenging due to their ability to act as antioxidants and their instability under various environmental conditions. In this study, we investigated the kinetics of black carrot anthocyanin degradation and the subsequent color loss influence...

Background In food production, re‐feeding material into the manufacturing process is common practice to meet ecological and economical requirements. In production of hamburgers, the products with external imperfections are re‐fed in a frozen, coarsely crushed state. Results In this study, the influence of the addition of frozen, pre‐crushed hambur...

Meat grinders are composed of a combination of individual functional elements (e.g., screw conveyor, perforated plates, knives). This setup, and in particular the chosen cutting set, influences the characteristics of ground meat and hamburgers produced. In this study, we took a closer look at the effect of cutting set variations and process paramet...

Food-material poses a challenging matrix for objective material scientific description that matches the consumers' perception. With eyes on the emerging structured food materials from alternative protein sources, objectively describing perceived texture characteristics became a topic of interest to the food industry. This work made use of the well-...

This review is providing an overview of the actual and past research in the field of ground meat. The forces that are acting in the meat grinder are well understood. The higher the forces that are acting on the meat while grinding, the stronger the disintegration of the meat cells after the process. These forces can be calculated as energy transfer...

Background Binding agents have emerged as an important and required class of ingredients to manufacture a wide range of new food products, especially semi-solid or solid vegan meat and dairy analogues. Scope and Approach In this review, we give a definition for this class of ingredients, look at what constitutes required functionalities for binders...

Meat color is an important aspect for the meat industry since it strongly determines the consumers’ perception of product quality and thereby significantly influences the purchase decision. Emergence of new vegan meat analogs has renewed interest in the fundamental aspects of meat color in order to replicate it. The appearance of meat is based on a...

The impact of temperature-controlled smoldering smoking conditions on the accumulations of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs) in Frankfurter-type sausages was investigated. Depending on the temperature, smoking can be divided into two phases: an unstable pyrolysis stage (≈ 200 s) and a stable pyrolysis stage (>200...

Smoking is used to give food its typical aroma and to obtain the desired techno-functional properties of the product. To gain a deeper knowledge of the whole process of food smoking, a controllable smoking process was developed, and the influence of wood pyrolysis temperature (150–900 °C) on the volatile compounds in the smoking chamber atmosphere...

The meat industry is typically using a mixture of fresh and frozen meat batters for minced meat production. Our goal was to find the exact threshold for fresh to frozen meat ratio capable of controlling the meat temperature during processing, but without having an adverse effect on the sensory quality of minced pork. To achieve this, the percentage...

So-called meat hybrids are a new class of products where a fraction of the meat product (e.g., 20%) is replaced with alternative protein sources, such as plant-based ones. Research suggests that these products could serve as a low-threshold offer for a specific target group that wants to cut down on meat, thereby facilitating the transition toward...

Structure-sensory relationships are essential for understanding food perception. Food microstructure impacts how a food is comminuted and processed by the human masticatory system. This study investigated the impact of anisotropic structures, explicitly the structure of meat fibers, on the dynamic process of mastication. For a general understanding...

BACKGROUND Binders in plant‐based meat analogues allow different components, such as extrudate and fat particles, to stick together. Typically, binders then are solidified to transform the mass into a non‐sticky, solid product. As an option for a clean‐label binder possessing such properties, the solidification behavior of pea protein–pectin mixtur...

Methylcellulose is commonly used in meat analogues for binding ingredients. In this study, we compared the binding properties of a methylcellulose hydrogel (5% w/w) to a novel, clean-label binder based on a mixture of pea protein and sugar beet pectin (r = 2:1, 22.5% w/w, pH 6.0) with and without laccase addition in a burger type meat analogue. It...

A bacon-type meat analogue consists of different structural layers, such as textured protein and a fat mimetic. To obtain a coherent and appealing product, a suitable binder must glue those elements together. A mixture based on pea protein and sugar beet pectin (r = 2:1, 25% w/w solids, pH 6) with and without laccase addition and a methylcellulose...

This study investigated the influence of saponin glycyrrhizin on the formation and stability of solid lipid nanoparticles. The hypothesis was that glycyrrhizin facilitates the formation of stable crystalline lipid particles due to its molecular characteristics and slows down polymorphic transition. Tristearin solid lipid nanoparticles emulsified wi...

Objective The objective of this study was to investigate the effect of pH change of cooked cured pork M. longissimus thoracis et lumborum on iridescence intensity and extent (= percentage of iridescent area) since interaction with light may be related to pH-induced alterations in microstructure. Muscles were injected with brines of different pH val...

Food products often consist of several phases. Comminuted meat products, for example, are multiphase systems consisting of structured meat particles and unstructured batter-like substance. To develop and understand the processing of these products, it is important to understand the sensory and mechanical perception principles. To this end, two-phas...

Larger processing equipment to produce minced meat could affect its structure due to intensive processing and a high energy intake in the meat mass. To assess if this would result in alterations in the minced meat quality, finely chopped meat (FCM) was added in different concentrations (15, 30, 45, 60, 75, 90, and 100%) to minced meat and quality p...

The utilization of heat is one of the foundations of modern food processing. At present, boilers that operate on fossil fuels are still dominating the generation of hot water, steam, and hot air in the food industry. In light of sustainability goals and carbon taxes as well as international efforts to reduce the dependence on natural gas, new techn...

The determination of the amount of non-intact cells (ANIC) in ground beef products is usually performed using a time-consuming and subjective histometric approach neglecting structural properties, which is why more objective and faster methods including evaluation of quality parameters are needed. To determine, whether the addition of meat batter i...

Food binders must be sticky to glue different components together. This study evaluated the impact of homogenization of pea proteins on the stickiness of pea protein – apple pectin mixtures. A reduction in protein particle size was suggested to improve adhesion and cohesion by increasing reactive surface area, resulting in a sticky material. In add...

Foams are essential in many food applications and require surface‐active ingredients such as proteins for formation and stabilization. We investigated the influence of high‐pressure homogenization on foaming properties of insoluble pea protein dispersions (5% w/w) at pH 3 and 5. Unhomogenized insoluble pea protein dispersions did not foam at either...

Many of the currently used binding agents such as methylcellulose are not clean label. A key property of binding agents or so-called “food glues” is their stickiness, a property that is governed by a balance between adhesion, i.e. the ability to stay attached to other structures or surfaces, and cohesion, i.e. the internal strength of a material to...

Stickiness is the combination of adhesion and cohesion and key characteristic for binders in foods to combine particulates into a coherent mass. We investigated the influence of mixing ratio of pea protein and apple pectin powders (w/w) at pH 6 on stickiness by assessing textural, rheological, and binding properties of a concentrated suspension (25...

Biofilm formation of Listeria monocytogenes on stainless steel, a widely used abiotic surface in the food processing industry, was investigated by focusing on the attachment tendency and behavior of L. monocytogenes 08-5578 on eight different stainless steel surfaces: glass bead blasted (rough and fine), deburred (Timesaver), drum deburred, pickled...

Besides the flavor profile of food, texture plays a major role in terms of the acceptance and likeability of food products. In contrast to gel-like homogenous isotropic structures, where the characterization is established and structure-texture mechanisms are well understood, there is still a lack of knowledge in the field of anisotropic complex fo...

In hamburger manufacturing, meat is subjected to four main processing steps (pre-grinding, mixing, grinding, and forming), whereby muscle fibers are disintegrated. In this study, the influence of these process steps was characterized by structural (amount of non-intact cells (ANIC), CLS-Microscopy), functional (drip loss) and qualitative (soluble p...

In this study, the characteristics of pea protein isolates after aqueous fractionization into water-soluble and water-insoluble fractions by centrifugation, decantation, and lyophilization were studied. Chemical composition and physicochemical properties upon pH changes were determined. The overall protein compositions of both soluble and insoluble...

Phycocyanin is a protein-chromophore structure present in Arthrospira platensis commonly used as a blue-colorant in food. Color losses of phycocyanin can be reduced by electrostatic complexation with λ-carrageenan. The aim of this study was to investigate the effect of molecular weight ( M W ) of λ-carrageenan on the color stabilization of electros...

Hybrid meat products represent a promising, more sustainable alternative to all-meat formulations. However, differences among plant- and animal-based proteins may alter traditional handling and final product properties. In this study, pork meat was partially replaced with texturized pumpkin seed proteins at 12.5, 25, 37.5, and 50% to obtain dry-cur...

The protein chromophore complex present in cyanobacteria like Arthrospira platensis can be utilized as a natural food colorant, but the appearance is prone to changes under environmental conditions that alter the protein-chromophore interactions. The study investigates the color stability of phycocyanin stabilized by λ-carrageenan during storage at...

Canola oil was structured by incorporation into a transglutaminase-induced covalently crosslinked network of soy proteins in order to mimic characteristics of animal fat tissue. Wheat fibers (3 and 6%) with fiber lengths of 30, 150, and 400 µm were added, which increased hardness, but did not notably affect the desired elastic properties. The anima...

Complex formation (leading to either coacervation or precipitation) offers a tool to generate plant-based novel food structures and textures. This study investigated the formation of complexes between soluble pea proteins and apple pectin upon varying the protein-to-pectin ratio ( r = 2:1 to 10:1), pH (3–7), and temperature (25 and 85 °C) with a to...

The effect of replacing 20% pork meat in cooked sausages by Pea Protein Isolate (PPI), pea Low Moisture Extrudates (LME), and pea High Moisture Extrudate (HME) on the nutritional, techno-functional and sensorial properties of emulsified cooked sausages was investigated. All hybrid sausages contained all essential amino acids in sufficient amounts....

Fibers of potato protein and polysaccharides were obtained by needleless electrospinning. Mixtures of maltodextrin DE2 (dextrose equivalent) (0.8 g/mL), DE21 (0.1 g/mL), and different concentrations of potato protein (0.05, 0.1, 0.15, and 0.2 g/mL) were used for fiber production. Glycation was performed via the Maillard reaction after thermal treat...

The increasing use of wet texturized plant proteins as meat substitutes requires a characterization of their functional properties, especially in terms of pH‐behavior when being mixed with meat proteins to create so‐called hybrid products. In this study, a minced model system containing pork meat, curing salt, and various amounts (0–100 wt%) of wet...

Dry fractionated legume protein ingredients are gaining attention as alternatives to conventional solvent extracted legume proteins, being more resource efficient and often exhibiting novel functional properties. However, lack of knowledge about the relationship between composition and functionality limit a more wide-spread use of dry-fractionated...

Homogenisation is an important process step in the production of aerosol whipping cream (AWC). In this study, the effect of homogenisation pressure (0 to 20 MPa, one-stage and two-stage) on AWC with and without addition of a saturated monoacylglyceride of medium chain length (me-sMAG) was investigated. Particle size distribution via static light sc...

The pH and temperature sensitivity of the natural blue pigment phycocyanin from Arthrospira platensis limits its application as food colorant. This study examines the effect of protein stabilization by the anionic polysaccharide λ-carrageenan on phycocyanins color appearance at pH 2.5–6.0, unheated and after heat treatments (70/90 °C). Electrostati...

Hypothesis. The emulsifying ability of starch is influenced by its molecular weight. Reducing the molecular weight of starch is expected to influence interfacial adsorption and membrane elasticities, thereby affecting its emulsifying ability through Pickering effects. Hence, it should be possible to tailor the emulsifying ability of starch by adjus...

The objective of this study was to investigate the effect of salt concentration on meat iridescence in cured cooked pork products. In addition, the influence of nitrite and pigmentary color on iridescence and its visual macroscopic perception was ascertained. Sample cubes from the pigs M. longissimus thoracis et lumborum were salted with either NaC...

The exchange of animal-based for plant-based proteins is becoming more and more popular due to an increasing demand for alternative and more sustainable protein sources. In this study, solubilized water- (ws) or salt-and-water (sws) meat proteins were evaluated in their pH-dependent interactions with soluble protein fractions from wheat, pumpkin, s...

This article provides an overview of key ethnic German meat products including dry-cured hams, fermented spreadable and sliceable sausages, emulsion-type sausages, and cooked sausages such as blood, jellied brawn, and liver sausages. The characteristics of flavor and consistency as well as manufacturing processes of these products are presented. Th...

The effect of Hofmeister salts (NaCl, NaSCN, Na 2 SO 4 , KCl, LiCl, CaCl 2 ) on surface iridescence in cooked pork was investigated. Strongest iridescence occurred in samples treated with NaSCN, NaCl and KCl. Control samples and LiCl, CaCl 2 and Na 2 SO 4 treatments showed weaker iridescence. However, differences between KCl and LiCl, CaCl2 and Na...

There is an increasing demand to develop and characterize high moisture extrudates from alternative plant proteins due to their increased use in various foods. In this study, wet texturized proteins from two pea isolates and four oilseed flours from pumpkin and sunflower were subjected to an acid titration to gain insights into their buffering capa...

High levels of meat consumption are increasingly being criticised for ethical, environmental, and social reasons. Plant-based meat substitutes have been identified as healthy sources of protein in comparison to meat. This alternative offers several social, environmental, and health benefits and may reduce meat consumption. However, there has been a...

Core-shell nanofibers were electrospun from bilayer gelatin/gum arabic corn oil-in-water emulsions crosslinked by genipin. The crosslinking increased the apparent viscosity and induced a predominantly elastic behavior of the emulsions, which favored the formation of a more stable emulsion system and then electrospun fibers with larger diameters. Th...

Dry fractionation has shown to be a promising method to obtain less refined protein ingredients from legumes with novel technofunctionalities compared to solvent extracted protein isolates. However, the relationship between composition and functionality of such fractions especially for use as emulsifiers in concentrated emulsions is still unclear....

To feed the world's growing population in the future, there must be a protein transition from animal-based to more sustainable, plant-based sources. Hybrid plant-meat products can bridge the protein-transition and are also focused on nutritional and sustainability aspects. While the addition of powdered proteins changes the texture of meat products...

The production of ultrafine fibers of proteins and polysaccharides by needleless electrospinning can be performed prior to a thermal treatment to form glycoconjugates via the first stage of the Maillard reaction. The aim was to produce potato protein–maltodextrin conjugates with a varying protein content of 0.05, 0.1, 0.15, and 0.2 g/mL by needlele...

BACKGROUND The use of plant proteins as food ingredients might be limited due to the presence of foreign or ‘off’ flavors, which may evolve during extraction and subsequent processing. In this study, the influence of dry (TVP) and wet (WTP) texturization on characteristic volatile compounds of two different pea protein isolates was assessed using g...

Existing complex meat analogues such as bacon often do not resemble meat-based ones in appearance, texture and techno-functionality. This has been due to them being only composed of a differently colored homogeneous protein matrix, but lack in presence of a fat phase which contributes to frying performance and taste perception. We hypothesized that...

Microstructural factors associated with surface iridescence in cooked, cured pork products were investigated. Meat iridescence is a commonly observed physical phenomenon in raw meat and meat products that consist of intact muscle tissue. Since the purchase decision of consumers is mainly driven by the first impression of meat color and appearance,...

BACKGROUND In the presence of ascorbic acid, the degradation of acylated (sinapic, ferulic and p‐coumaric acid derivatives of cyanidin‐3‐xylosylglucosylgalactoside) and non‐acylated anthocyanins of black carrot extract (BCE) encapsulated in liposomes was studied. BCEs (0.2% and 0.4% w/w) were encapsulated in liposomes using different lecithin conce...

Recently an approach has been developed to structure plant-based lipids with the intention to mimic animal fat tissue in processed meat products or analogues. This study investigated the comminution behavior in a bowl chopper of such structured lipids with varying mechanical properties. For products like salami-type sausages these systems need to w...

Partial fat replacement in cooked salamis was formulated using organogels made with canola oil, ethylcellulose (EC; 6, 8, 9, 10, 11, 12 and 14%) and three types of surfactants; i.e., glycerol monostearate (GMS), stearyl alcohol/stearic acid (SOSA) and soybean lecithin (Lec). Texture profile analysis (TPA) and back extrusion tests indicated that inc...

Technofunctional properties of plant proteins deviate from those of animal-derived proteins and make their combination in foods challenging. In this work, proteins from a soluble, low-molecular weight potato protein fraction (<24 kDa) and pork meat were salt-solubilized (1.8 wt % NaCl) and mixed in a 50:50 (v/v) ratio to assess their miscibility at...

Background Biosurfactants are surface-active molecules produced by different microorganisms and display a promising alternative to synthetically derived food emulsifiers. One of these biosurfactants, synthesized by Bacillus subtilis, is the lipopeptide surfactin, which composes a linear fatty acid and cyclic peptide moiety. This study explores the...

Proteins obtained from alternative sources such as plants, microorganisms, and insects have attracted considerable interest in the formulation of new food products that